Programming Information for WiNRADiO G35DDC HF receiver in coherent mode.

The G35DDC API SDK is implemented as a 32-bit dynamic library (G35DDCAPI.dll). It provides object-oriented and non-object-oriented interfaces to control set of G35DDC devices in coherent mode. This document describes the non-object-oriented interface. The G35DDCAPI.dll library exports several functions that make it possible to control G35DDC receivers in coherent mode.

The API is not fully thread-safe so preferrably it should be used in single-threaded applications. It can be used in multi-threaded applications as well, but with some care: One set of G35DDC receivers can be controlled from a single user thread only.

A C/C++ header file G35DDCAPI.h is a part of the SDK. The API can be used by any 32-bit application under Microsoft Windows 2000, XP, Vista, Windows 7 and Windows 8 (including their 64-bit versions).

Processing chain block diagram of G35DDC device set in coherent mode

The G35DDC device set in coherent mode can consist of up to 8 interconnected G35DDC devices. DDC1 signals from all the G35DDC devices in such set are phase-coherent. All other provided signals (IF, DDC2 and audio) are not phase-coherent. Only one processing channel per device is available in coherent mode.

Simplified block diagram of G35DDC processing chain
Attenuator Preselectors Preamplifier Noise blanker IF DDC1 frequency shift DDC1 DDC1 stream DDC2 frequency shift DDC2 DDC2 stream DDC2 noise blanker Demodulator filter Signal level Notch filters Gain Pre-processed DDC2 stream Demodulator Audio gain Audio stream Audio filter Set volume Attenuator Preselectors Preamplifier Noise blanker IF DDC1 frequency shift DDC1 DDC1 stream DDC2 frequency shift DDC2 DDC2 stream DDC2 noise blanker Demodulator filter Signal level Notch filters Gain Pre-processed DDC2 stream Demodulator Audio gain Audio stream Audio filter Set volume Attenuator Preselectors Preamplifier Noise blanker IF DDC1 frequency shift DDC1 DDC1 stream DDC2 frequency shift DDC2 DDC2 stream DDC2 noise blanker Demodulator filter Signal level Notch filters Gain Pre-processed DDC2 stream Demodulator Audio gain Audio stream Audio filter Set volume Simplified block diagram of the device set processing chain containing three interconnected G35DDC devices in coherent mode.
Phase-coherent parts of the device set are in the red rectangles.

Using WiNRADiO G35DDC API

Loading API

The G35DDCAPI.dll library can be loaded to the application by two Microsoft Windows API functions. The first one is LoadLibrary and the other one is LoadLibraryEx. After the library is loaded, it is required to get addresses of exported functions. When the API is no longer required in the memory, the FreeLibrary function can be used to unload the API. Before the FreeLibrary is called, all the handles to G35DDC device sets returned by the CohOpenDeviceSet function must be closed by the CohCloseDeviceSet function, otherwise the application can become to unpredictable state.

The following source code shows how to load the API.

 

#include <stdio.h>

#include "G35DDCAPI.h"



COH_G35DDC_OPEN_DEVICE_SET CohOpenDeviceSet;

COH_G35DDC_CLOSE_DEVICE_SET CohCloseDeviceSet;

HMODULE hAPI;



void main(void)

{  

    //Loading the API

    hAPI=LoadLibrary("G35DDCAPI.dll");



    if(hAPI!=NULL)

    {

        //Retrieving addresses of used API functions

        CohOpenDeviceSet=(COH_G35DDC_OPEN_DEVICE_SET)GetProcAddress(hAPI,"CohOpenDeviceSet");

        CohCloseDeviceSet=(COH_G35DDC_CLOSE_DEVICE_SET)GetProcAddress(hAPI,"CohCloseDeviceSet");



        //Here place code that uses the API



        FreeLibrary(hAPI);

    }

    else

    {

        //If the LoadLibrary fails

        printf("Failed to load G35DDCAPI.dll.\n");

    }

}

List of available G35DDC device sets in coherent mode

The G35DDC API provides the CohGetDeviceSetList function which returns list of available G35DDC device sets which can be open using the CohOpenDeviceSet function.

The following source code produces list of serial numbers of G35DDC devices of available device sets.


#include <stdio.h>

#include "G35DDCAPI.h"



COH_G35DDC_GET_DEVICE_SET_LIST CohGetDeviceSetList;

COH_G35DDC_FREE_DEVICE_SET_LIST CohFreeDeviceSetList;

HMODULE hAPI;



void main(void)

{

 UINT32 i,j;

 COH_G35DDC_DEVICE_SET_LIST *DeviceSetList;



    //Loading the API

    hAPI=LoadLibrary("G35DDCAPI.dll");



    if(hAPI!=NULL)

    {

        //Retrieving address of the CohGetDeviceSetList and CohFreeDeviceSetList functions

        CohGetDeviceSetList=(COH_G35DDC_GET_DEVICE_SET_LIST)GetProcAddress(hAPI,"CohGetDeviceSetList");

        CohFreeDeviceSetList=(COH_G35DDC_FREE_DEVICE_SET_LIST)GetProcAddress(hAPI,"CohFreeDeviceSetList");

        

        DeviceSetList=CohGetDeviceSetList();

        

        if(DeviceSetList!=NULL)

        {            

            if(DeviceSetList->DeviceSetCount!=0)

            {

                printf("Available G35DDC device set count=%d\n",DeviceSetList->DeviceSetCount);

                                

                for(i=0;i<DeviceSetList->DeviceSetCount;i++)

                {

                    printf("Device set %u:\n",i);

                    printf("\tNumber of devices in the set: %u\n",DeviceSetList->DeviceSet[i].DeviceCount);

                    

                    for(j=0;j<DeviceSetList->DeviceSet[i].DeviceCount;j++)

                    {

                        printf("\t\t%u: SN: %s\n",j,DeviceSetList->DeviceSet[i].DeviceInfo[j].SerialNumber);

                    }

                }                

            }

            else

            {

                printf("No available G35DDC device set has been found.\n");

            }

            

            //free memory

            CohFreeDeviceSetList(DeviceSetList);

        }

        else

        {

            printf("CohGetDeviceSetList failed with error %08X\n",GetLastError());

        }



        FreeLibrary(hAPI);

    }

    else

    {

        printf("Failed to load G35DDCAPI.dll.\n");

    }



    printf("Press enter to exit\n");

    getchar();

}

Opening G35DDC device set

G35DDC device set has to be open before it can be controlled. The API provide the CohOpenDeviceSet function to open device set of interconnected G35DDC devices in coherent mode.

The following source code shows how to open the first available G35DDC device set.


#include <stdio.h>

#include "G35DDCAPI.h"



COH_G35DDC_OPEN_DEVICE_SET CohOpenDeviceSet;

COH_G35DDC_CLOSE_DEVICE_SET CohCloseDeviceSet;

HMODULE hAPI;



void main(void)

{  

 INT32 hDeviceSet;

 

    //Loading the API

    hAPI=LoadLibrary("G35DDCAPI.dll");



    if(hAPI!=NULL)

    {

        //Retrieving addresses of the CohOpenDeviceSet and CohCloseDeviceSet API functions

        CohOpenDeviceSet=(COH_G35DDC_OPEN_DEVICE_SET)GetProcAddress(hAPI,"CohOpenDeviceSet");

        CohCloseDeviceSet=(COH_G35DDC_CLOSE_DEVICE_SET)GetProcAddress(hAPI,"CohCloseDeviceSet");



        //Opening the first available G35DDC device set using predefined G35DDC_OPEN_FIRST_SET constant

        hDeviceSet=CohOpenDeviceSet(G35DDC_OPEN_FIRST_SET,0);

        

        if(hDeviceSet>=0)

        {

            //Here place code that works with the open G35DDC device set            

            

            //Closing handle to opened G35DDC device set

            CohCloseDeviceSet(hDeviceSet);

        }

        else

        {

            printf("CohOpenDeviceSet failed with error %08X\n",GetLastError());

        }



        FreeLibrary(hAPI);

    }

    else

    {

        //If the LoadLibrary fails

        printf("Failed to load G35DDCAPI.dll.\n");

    }

}

The following code demonstrates another way to open the first available G35DDC device set using device set list.

#include <stdio.h>

#include "G35DDCAPI.h"



COH_G35DDC_OPEN_DEVICE_SET CohOpenDeviceSet;

COH_G35DDC_CLOSE_DEVICE_SET CohCloseDeviceSet;

COH_G35DDC_GET_DEVICE_SET_LIST CohGetDeviceSetList;

COH_G35DDC_FREE_DEVICE_SET_LIST CohFreeDeviceSetList;

HMODULE hAPI;



void main(void)

{  

 INT32 hDeviceSet;

 COH_G35DDC_DEVICE_SET_LIST *DeviceSetList;

 

    //Loading the API

    hAPI=LoadLibrary("G35DDCAPI.dll");



    if(hAPI!=NULL)

    {

        //Retrieving addresses of API functions

        CohOpenDeviceSet=(COH_G35DDC_OPEN_DEVICE_SET)GetProcAddress(hAPI,"CohOpenDeviceSet");

        CohCloseDeviceSet=(COH_G35DDC_CLOSE_DEVICE_SET)GetProcAddress(hAPI,"CohCloseDeviceSet");

        CohGetDeviceSetList=(COH_G35DDC_GET_DEVICE_SET_LIST)GetProcAddress(hAPI,"CohGetDeviceSetList");

        CohFreeDeviceSetList=(COH_G35DDC_FREE_DEVICE_SET_LIST)GetProcAddress(hAPI,"CohFreeDeviceSetList");



        DeviceSetList=CohGetDeviceSetList();

        

        if(DeviceSetList!=NULL)

        {

            if(DeviceSetList->DeviceSetCount!=0)

            {

                //Opening the first available G35DDC device set in the list

                hDeviceSet=CohOpenDeviceSet(DeviceSetList->DeviceSet[0].DeviceInfo,DeviceSetList->DeviceSet[0].DeviceCount);

                

                if(hDeviceSet>=0)

                {

                    //Here place code that works with the open G35DDC device set            

                    

                    //Closing handle to opened G35DDC device set

                    CohCloseDeviceSet(hDeviceSet);

                }

                else

                {

                    printf("CohOpenDeviceSet failed with error %08X\n",GetLastError());

                }

            }

            else

            {

                printf("No available G35DDC device set has been found.\n");

            }

            

            CohFreeDeviceSetList(DeviceSetList);

        }

        else

        {

            printf("CohGetDeviceSetList failed with error %08X\n",GetLastError());

        }



        FreeLibrary(hAPI);

    }

    else

    {

        //If the LoadLibrary fails

        printf("Failed to load G35DDCAPI.dll.\n");

    }

}

CohGetDeviceSetList

The CohGetDeviceSetList function returns information about available G35DDC device sets that can be open.

C/C++ declaration

COH_G35DDC_DEVICE_SET_LIST* __stdcall CohGetDeviceSetList(void);

Address retrieval

COH_G35DDC_GET_DEVICE_SET_LIST CohGetDeviceSetList=(COH_G35DDC_GET_DEVICE_SET_LIST)GetProcAddress(hAPI,"CohGetDeviceSetList");

Parameters

None

Return value

If the function succeeds, the return value is non-zero pointer to a structure which describes list of available sets of interconnected G35DDC devices.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If the returned list of available device sets is no longer needed, memory used by this list has to be freed using the CohFreeDeviceSetList function.


CohFreeDeviceSetList

The CohFreeDeviceSetList function frees memory allocated by the CohGetDeviceSetList function. This memory is used to store list of available G35DDC device sets.

C/C++ declaration

void __stdcall CohFreeDeviceSetList(COH_G35DDC_DEVICE_SET_LIST *DeviceSetList);

Address retrieval

COH_G35DDC_FREE_DEVICE_SET_LIST CohFreeDeviceSetList=(COH_G35DDC_FREE_DEVICE_SET_LIST)GetProcAddress(hAPI,"CohFreeDeviceSetList");

Parameters

DeviceSetList
[in] Pointer to data structure returned by a previous call to the CohGetDeviceSetList function. This parameter cannot be NULL.

CohOpenDeviceSet

Opens G35DDC device set.

C/C++ declaration

INT32 __stdcall CohOpenDeviceSet(G35DDC_DEVICE_INFO *DeviceInfos,UINT32 Count);

Address retrieval

COH_G35DDC_OPEN_DEVICE_SET CohOpenDeviceSet=(COH_G35DDC_OPEN_DEVICE_SET)GetProcAddress(hAPI,"CohOpenDeviceSet");

Parameters

DeviceInfos
[in] Pointer to array of G35DDC_DEVICE_INFO structures which contains information about all the devices in the device set to be open. Number of items in the array is given by the Count parameter. Order of device info structures in the array has to correspond to hardware interconnect of G35DDC devices. Array of device info structures and its size can be obtained from the list of device set provided by the CohGetDeviceSetList function. The example above shows how to do it.

It is possible to use one of the following predefined values instead of pointer to the array:
ValueMeaning
G35DDC_OPEN_FIRST_SETThe function opens first available G35DDC device set. The Count parameter is ignored, number of interconnected devices is determined automatically.
G35DDC_OPEN_DEMO_SETThe function opens demo G35DDC device set. This allows to work with the API without physical G35DDC devices. The Count parameter specifies number of demo receivers in the set and it can vary from 1 to 8.
Count
[in] Specifies the number of items in the array pointed to by the DeviceInfos parameter.

Return value

If the function succeeds, the return value is handle to the specified G35DDC device set. This handle can only be used with functions of G35DDC API.
If the function fails, the return value is negative. To get extended error information, call GetLastError.

Remarks

The CohOpenDeviceSet function can be called from any user thread, the returned handle can only be used in the same thread, otherwise application can become to unpredictable state.

Use the CohCloseDeviceSet function to close G35DDC device set handle returned by CohOpenDeviceSet.

Order of devices in the device set corresponds to hardware interconnect of the G35DDC devices. Each individual devices in the device set has its own constant index that does not change while hardware G35DDC device interconnect is the same. This index is used in some API function to access specific device of the device set. Index of the first device is 0, index of the second device is 1, etc..


CohCloseDeviceSet

Closes G35DDC device set.

C/C++ declaration

BOOL __stdcall CohCloseDeviceSet(INT32 hDeviceSet);

Address retrieval

COH_G35DDC_CLOSE_DEVICE_SET CohCloseDeviceSet=(COH_G35DDC_CLOSE_DEVICE_SET)GetProcAddress(hAPI,"CohCloseDeviceSet");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohIsConnected

Checks if all the devices in the device set are still connected to the computer.

C/C++ declaration

BOOL __stdcall CohIsConnected(INT32 hDeviceSet);

Address retrieval

COH_G35DDC_IS_CONNECTED CohIsConnected=(COH_G35DDC_IS_CONNECTED)GetProcAddress(hAPI,"CohIsConnected");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.

Return value

The function returns non-zero value if all the devices in the set are still connected.
If a device is disconnected or the function fails return value is zero. To determine if the function failed, call GetLastError. GetLastError returns ERROR_SUCCESS if a device is disconnected or another error code if CohIsConnected failed.

Remarks

If it is determined the device is disconnected, corresponding device handle is no longer usable and it should be closed using the CloseDevice function.

CohGetDeviceCount

Retrieves number of G35DDC devices in the device set.

C/C++ declaration

BOOL __stdcall CohGetDeviceCount(INT32 hDeviceSet,UINT32 *Count);

Address retrieval

COH_G35DDC_GET_DEVICE_COUNT CohGetDeviceCount=(COH_G35DDC_GET_DEVICE_COUNT)GetProcAddress(hAPI,"CohGetDeviceCount");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Count
[out] Pointer to a variable that receives number of G35DDC devices in the device set. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetDeviceInfo

Retrieves information about the G35DDC device.

C/C++ declaration

BOOL __stdcall CohGetDeviceInfo(INT32 hDeviceSet,UINT32 DeviceIndex,G35DDC_DEVICE_INFO *Info);

Address retrieval

COH_G35DDC_GET_DEVICE_INFO CohGetDeviceInfo=(COH_G35DDC_GET_DEVICE_INFO)GetProcAddress(hAPI,"CohGetDeviceInfo");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set. Order of the devices corresponds to hardware interconnect of physical G35DDC devices.
Info
[out] Pointer to a G35DDC_DEVICE_INFO structure to be filled with information about the device. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetDeviceCount function to determine number of devices in the device set.

CohGetDeviceInfos

Retrieves information about all the G35DDC devices in the device set at once.

C/C++ declaration

BOOL __stdcall CohGetDeviceInfos(INT32 hDeviceSet,G35DDC_DEVICE_INFO *Infos,UINT32 *InfoCount);

Address retrieval

COH_G35DDC_GET_DEVICE_INFOS CohGetDeviceInfos=(COH_G35DDC_GET_DEVICE_INFOS)GetProcAddress(hAPI,"CohGetDeviceInfos");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Infos
[out] Pointer to array of G35DDC_DEVICE_INFO structures to be filled with information about device in the device set.
Order of the device infos in the array corresponds to hardware interconnect of physical G35DDC devices.
InfoCount
[in, out] Pointer to a variable that specifies size of the array (number of items in the array) pointed to by the Infos parameter. When the function returns, this variable contains number of items copied to Infos.

If the array specified by Infos parameter is not large enough to hold information about all the devices in the device set, the function fails (GetLastError returns ERROR_INSUFFICIENT_BUFFER) and stores the required array size (number of items) in the variable pointed to by the InfoCount parameter.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetDeviceCount function to determine number of devices in the device set.

CohSetPower

Turns on or off all the G35DDC devices in the device set.

C/C++ declaration

BOOL __stdcall CohSetPower(INT32 hDeviceSet,BOOL Power);

Address retrieval

COH_G35DDC_SET_POWER CohSetPower=(COH_G35DDC_SET_POWER)GetProcAddress(hAPI,"CohSetPower");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Power
[in] Specifies whether to turn on or off the devices. If this parameter is non-zero all the device in the device set are turned on, if it is zero all the devices are turned off.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If CohSetPower turns the devices off, all the running streams are stopped.

Use the CohGetPower function to determine current power state of devices in the device set.


CohGetPower

The GetPower function determines whether the devices are turned on or off.

C/C++ declaration

BOOL __stdcall CohGetPower(INT32 hDeviceSet,BOOL *Power);

Address retrieval

COH_G35DDC_GET_POWER CohGetPower=(COH_G35DDC_GET_POWER)GetProcAddress(hAPI,"CohGetPower");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Power
[out] Pointer to a variable that receives current power state of the device set. If it is non-zero, the devices are turned on. If it is zero the devices are turned off. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetAttenuator

Sets input attenuator.

C/C++ declaration

BOOL __stdcall CohSetAttenuator(INT32 hDeviceSet,UINT32 Attenuator);

Address retrieval

COH_G35DDC_SET_ATTENUATOR CohSetAttenuator=(COH_G35DDC_SET_ATTENUATOR)GetProcAddress(hAPI,"CohSetAttenuator");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Attenuator
[in] Value that specifies attenuation level in dB. Possible values are: 0, 3, 6, 9, 12, 15, 18, 21. If the value is not from the list, the CohSetAttenuator function rounds the value to nearest lower one.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetAttenuator function to determine current setting of the attenuator.

CohGetAttenuator

Retrieves current setting of the attenuator.

C/C++ declaration

BOOL __stdcall CohGetAttenuator(INT32 hDeviceSet,UINT32 *Attenuator);

Address retrieval

COH_G35DDC_GET_ATTENUATOR CohGetAttenuator=(COH_G35DDC_GET_ATTENUATOR)GetProcAddress(hAPI,"CohGetAttenuator");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Attenuator
[out] Pointer to a variable that receives current attenuation level. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetPreselectors

Controls the band pass filter at input.

C/C++ declaration

BOOL __stdcall CohSetPreselectors(INT32 hDeviceSet,UINT32 Low,UINT32 High);

Address retrieval

COH_G35DDC_SET_PRESELECTORS CohSetPreselectors=(COH_G35DDC_SET_PRESELECTORS)GetProcAddress(hAPI,"CohSetPreselectors");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Low
[in] Specifies cut-off low frequency of the filter in Hz. Possible values are: 0, 850000, 2400000, 5400000, 11800000. If the value is not from the list, the function rounds it to nearest one.
High
[in] Specifies cut-off high frequency of the filter in Hz. Possible values are: 3100000, 5400000, 11800000, 23300000, 50000000. If the value is not from the list, the function rounds it to nearest one.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Value of the Low parameter must not be higher than value of the High parameter, otherwise the function fails.

Use the CohGetPreselectors function to determine current setting of the preselectors.


CohGetPreselectors

Retrieves current setting of input band pass filter.

C/C++ declaration

BOOL __stdcall CohGetPreselectors(INT32 hDeviceSet,UINT32 *Low,UINT32 *High);

Address retrieval

COH_G35DDC_GET_PRESELECTORS CohGetPreselectors=(COH_G35DDC_GET_PRESELECTORS)GetProcAddress(hAPI,"CohGetPreselectors");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Low
[out] Pointer to a variable that receives current cut-off low frequency of the filter in Hz. This parameter can be NULL if the application does not require this information.
High
[out] Pointer to a variable that receives current cut-off high frequency of the filter in Hz. This parameter can be NULL if the application does not require this information.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetPreamp

Enables or disables input preamplifier.

C/C++ declaration

BOOL __stdcall CohSetPreamp(INT32 hDeviceSet,BOOL Preamp);

Address retrieval

COH_G35DDC_SET_PREAMP CohSetPreamp=(COH_G35DDC_SET_PREAMP)GetProcAddress(hAPI,"CohSetPreamp");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Preamp
[in] Specifies whether to enable or disable preamplifier. If this parameter is non-zero, the preamplifier is enabled. If the parameter is zero, the preamplifier is disabled.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetPreamp function to determine current state of the preamplifier.


CohGetPreamp

Retrieves current state of input preamplifier.

C/C++ declaration

BOOL __stdcall CohGetPreamp(INT32 hDeviceSet,BOOL *Preamp);

Address retrieval

COH_G35DDC_GET_PREAMP CohGetPreamp=(COH_G35DDC_GET_PREAMP)GetProcAddress(hAPI,"CohGetPreamp");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Preamp
[out] Pointer to a variable that receives current state of the preamplifier. The value is non-zero if the preamplifier is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetADCNoiseBlanker

Enables or disables noise blanker on ADC stream.

C/C++ declaration

BOOL __stdcall CohSetADCNoiseBlanker(INT32 hDeviceSet,BOOL Enabled);

Address retrieval

COH_G35DDC_SET_ADC_NOISE_BLANKER CohSetADCNoiseBlanker=(COH_G35DDC_SET_ADC_NOISE_BLANKER)GetProcAddress(hAPI,"CohSetADCNoiseBlanker");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Enabled
[in] Specifies whether to enable or disable noise blanker. If this parameter is non-zero, noise blanker is enabled. If the parameter is zero, noise blanker is disabled.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetADCNoiseBlanker function to determine current state of the noise blanker.

CohGetADCNoiseBlanker

Retrieves current ADC noise blanker state.

C/C++ declaration

BOOL __stdcall CohGetADCNoiseBlanker(INT32 hDeviceSet,BOOL *Enabled);

Address retrieval

COH_G35DDC_GET_ADC_NOISE_BLANKER CohGetADCNoiseBlanker=(COH_G35DDC_GET_ADC_NOISE_BLANKER)GetProcAddress(hAPI,"CohGetADCNoiseBlanker");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Enabled
[out] Pointer to a variable that receives current state of noise blanker. The value is non-zero if noise blanker is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetADCNoiseBlankerThreshold

Specifies ADC noise blanker threshold.

C/C++ declaration

BOOL __stdcall CohSetADCNoiseBlankerThreshold(INT32 hDeviceSet,WORD Threshold);

Address retrieval

COH_G35DDC_SET_ADC_NOISE_BLANKER_THRESHOLD CohSetADCNoiseBlankerThreshold=

    (COH_G35DDC_SET_ADC_NOISE_BLANKER_THRESHOLD)GetProcAddress(hAPI,"CohSetADCNoiseBlankerThreshold");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Threshold
[in] Specifies the maximum acceptable input signal. Maximum possible value of threshold is 32767, in this case the noise blanker has no effect even it is enabled using the CohSetADCNoiseBlanker function.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetADCNoiseBlankerThreshold function to retrieve current threshold of the noise blanker.

CohGetADCNoiseBlankerThreshold

Determines ADC noise blanker threshold.

C/C++ declaration

BOOL __stdcall CohGetADCNoiseBlankerThreshold(INT32 hDeviceSet,WORD *Threshold);

Address retrieval

COH_G35DDC_GET_ADC_NOISE_BLANKER_THRESHOLD CohGetADCNoiseBlankerThreshold=

    (COH_G35DDC_GET_ADC_NOISE_BLANKER_THRESHOLD)GetProcAddress(hAPI,"CohGetADCNoiseBlankerThreshold");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Threshold
[out] Pointer to a variable that receives threshold of ADC noise blanker. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohStartIF

Starts sending of IF snapshots from specific device of the device set.

C/C++ declaration

BOOL __stdcall CohStartIF(INT32 hDeviceSet,UINT32 DeviceIndex,WORD Period);

Address retrieval

COH_G35DDC_START_IF CohStartIF=(COH_G35DDC_START_IF)GetProcAddress(hAPI,"CohStartIF");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Period
[in] Specifies time interval in milliseconds how often the IF snapshot is taken and sent to IFCallback callback function.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The G35DDC device has to be turned on using the CohSetPower function before use of CohStartIF, otherwise the CohStartIF function fails.


CohStopIF

Stops sending of IF snapshots from specific device of the device set.

C/C++ declaration

BOOL __stdcall CohStopIF(INT32 hDeviceSet,UINT32 DeviceIndex,);

Address retrieval

COH_G35DDC_STOP_IF CohStopIF=(COH_G35DDC_STOP_IF)GetProcAddress(hAPI,"CohStopIF");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The IFCallback callback function is not called after CohStopIF returns.


CohSetInverted

Enables or disables frequency spectrum inversion.

C/C++ declaration

BOOL __stdcall CohSetInverted(INT32 hDeviceSet,BOOL Inverted);

Address retrieval

COH_G35DDC_SET_INVERTED CohSetInverted=(COH_G35DDC_SET_INVERTED)GetProcAddress(hAPI,"CohSetInverted");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Inverted
[in] Specifies whether to enable or disable frequency spectrum inversion. If this parameter is non-zero, IF spectrum is inverted.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetInverted

Retrieves current frequency spectrum inversion setting.

C/C++ declaration

BOOL __stdcall CohGetInverted(INT32 hDeviceSet,BOOL *Inverted);

Address retrieval

COH_G35DDC_GET_INVERTED CohGetInverted=(COH_G35DDC_GET_INVERTED)GetProcAddress(hAPI,"CohGetInverted");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Inverted
[out] Pointer to a variable that receives non-zero value if the frequency spectrum inversion is enabled, and zero if the inversion is disabled. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetDDCInfo

Retrieves information about DDC format.

C/C++ declaration

BOOL __stdcall CohGetDDCInfo(INT32 hDeviceSet,UINT32 DDCTypeIndex,G3XDDC_DDC_INFO *Info);

Address retrieval

COH_G35DDC_GET_DDC_INFO CohGetDDCInfo=(COH_G35DDC_GET_DDC_INFO)GetProcAddress(hAPI,"CohGetDDCInfo");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DDCTypeIndex
[in] Specifies index of DDC type. For more information, see remarks.
Info
[out] Pointer to a G3XDDC_DDC_INFO structure to be filled with information about DDC type.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetDDC1Count function to determine the number of possible DDC types of DDC1. In this case the DDCTypeIndex parameter can vary from zero to one less than the number determined by CohGetDDC1Count.

Use the CohGetDDC1 function to determine current DDC type index of DDC1 and the CohGetDDC2 function to determine current DDC type of DDC2.


CohGetDDC1Count

Retrieves number of DDC types supported by DDC1.

C/C++ declaration

BOOL __stdcall CohGetDDC1Count(INT32 hDeviceSet,UINT32 *Count);

Address retrieval

COH_G35DDC_GET_DDC1_COUNT CohGetDDC1Count=(COH_G35DDC_GET_DDC1_COUNT)GetProcAddress(hAPI,"CohGetDDC1Count");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Count
[out] Pointer to a variable that receives number of DDC types supported by the DDC1. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDDC1

Sets current DDC type of DDC1.

C/C++ declaration

BOOL __stdcall CohSetDDC1(INT32 hDeviceSet,UINT32 DDCTypeIndex);

Address retrieval

COH_G35DDC_SET_DDC1 CohSetDDC1=(COH_G35DDC_SET_DDC1)GetProcAddress(hAPI,"CohSetDDC1");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DDCTypeIndex
[in] Specifies index of DDC type to be used in DDC1. It can vary from zero to one less than number of DDC types of the DDC1.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetDDC1Count function to determine the number of possible DDC types of DDC1. The DDCTypeIndex parameter can vary from zero to one less than the number determined by CohGetDDC1Count.

DDC1 streaming must not run when calling CohSetDDC1. In other words, DDC1 streaming that is started using the CohStartDDC1 function has to be stopped using the CohStopDDC1 function before calling of CohSetDDC1, otherwise CohSetDDC1 fails. The CohSetDDC1 function does not start and stop DDC1 streaming, just changes DDC type of DDC1.

Calling of CohSetDDC1 can change current DDC type of DDC2 and current bandwidth of demodulator filter, so it is useful to call the CohGetDDC2 and CohGetDemodulatorFilterBandwidth functions immediately after CohSetDDC1 to determine current DDC type of DDC2 and current bandwidth of demodulator filter.

Use the CohGetDDC1 function to determine current DDC type of the DDC1.


CohGetDDC1

Retrieves information about current DDC type of the DDC1.

C/C++ declaration

BOOL __stdcall CohGetDDC1(INT32 hDeviceSet,UINT32 *DDCTypeIndex,G3XDDC_DDC_INFO *DDCInfo);

Address retrieval

COH_G35DDC_GET_DDC1 CohGetDDC1=(COH_G35DDC_GET_DDC1)GetProcAddress(hAPI,"CohGetDDC1");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DDCTypeIndex
[out] Pointer to a variable that receives index of current DDC type of the DDC1. This parameter can be NULL if the application does not require this information.
DDCInfo
[out] Pointer to a G3XDDC_DDC_INFO structure to be filled with information about current DDC type of the DDC1. This parameter can be NULL if the application does not require this information.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Returned DDCTypeIndex can be passed to the CohGetDDCInfo function.

CohSetDDC1Frequency

Sets DDC1 center frequency.

C/C++ declaration

BOOL __stdcall CohSetDDC1Frequency(INT32 hDeviceSet,UINT32 Frequency);

Address retrieval

COH_G35DDC_SET_DDC1_FREQUENCY CohSetDDC1Frequency=(COH_G35DDC_SET_DDC1_FREQUENCY)GetProcAddress(hAPI,"CohSetDDC1Frequency");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Frequency
[in] Specifies new center frequency of DDC1 in Hz.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Changing of DDC1 frequency causes change of absolute frequency of the DDC2 and demodulator in each device in the set.

Use the CohGetDDC1Frequency function to determine current center frequency of DDC1.


CohGetDDC1Frequency

Retrieves current center frequency of DDC1.

C/C++ declaration

BOOL __stdcall CohGetDDC1Frequency(INT32 hDeviceSet,UINT32 *Frequency);

Address retrieval

COH_G35DDC_GET_DDC1_FREQUENCY CohGetDDC1Frequency=(COH_G35DDC_GET_DDC1_FREQUENCY)GetProcAddress(hAPI,"CohGetDDC1Frequency");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Frequency
[out] Pointer to a variable that receives current center frequency of DDC1 in Hz. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDDC1PhaseShift

Sets phase shift of DDC1 signal for specific device in the device set.

C/C++ declaration

BOOL __stdcall CohSetDDC1PhaseShift(INT32 hDeviceSet,UINT32 DeviceIndex,double PhaseShift);

Address retrieval

COH_G35DDC_SET_DDC1_PHASE_SHIFT CohSetDDC1PhaseShift=(COH_G35DDC_SET_DDC1_PHASE_SHIFT)GetProcAddress(hAPI,"CohSetDDC1PhaseShift");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
PhaseShift
[in] Specifies new phase shift of DDC1 signal in degrees at current DDC1 center frequency. It can vary from -180 to +180 degrees.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

It can be used for compensation of small length differences of cables used for coherent clock or at receiver RF inputs.

Use the CohGetDDC1PhaseShift function to retrieve current phase shift of DDC1 signal.


CohGetDDC1PhaseShift

Retrieves current phase shift of DDC1 signal of specific device in the device set.

C/C++ declaration

BOOL __stdcall CohGetDDC1PhaseShift(INT32 hDeviceSet,UINT32 DeviceIndex,double *PhaseShift);

Address retrieval

COH_G35DDC_GET_DDC1_PHASE_SHIFT CohGetDDC1PhaseShift=(COH_G35DDC_GET_DDC1_PHASE_SHIFT)GetProcAddress(hAPI,"CohGetDDC1PhaseShift");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
PhaseShift
[out] Pointer to a variable that receives current phase shift of DDC1 signal in degrees. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohStartDDC1

Starts coherent DDC1 streaming on all the devices in the set simultaneously.

C/C++ declaration

BOOL __stdcall CohStartDDC1(INT32 hDeviceSet,UINT32 SamplesPerBuffer);

Address retrieval

COH_G35DDC_START_DDC1 CohStartDDC1=(COH_G35DDC_START_DDC1)GetProcAddress(hAPI,"CohStartDDC1");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
SamplesPerBuffer
[in] Specifies number of I/Q sample sets in each buffer passed to the the DDC1StreamCallback callback function. The value has to be multiple of 64 greater than zero. If it is zero, the CohStartDDC1 function fails. If it is not multiple of 64 the function rounds it up to nearest multiple of 64.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The G35DDC devices have to be turned on using the CohSetPower function before CohStartDDC1 is used. Otherwise CohStartDDC1 fails.

If the DDC1 streaming is already running before use of CohStartDDC1, CohStartDDC1 restarts the streaming except it was previously started with the same SamplesPerBuffer parameter. In this case CohStartDDC1 does nothing. Restart of DDC1 streaming stops DDC2 and audio streaming in each device in the set. CohStartDDC1 does not restart DDC2 and audio streaming.

Use the CohStopDDC1 function to stop DDC1 streaming.

Decreasing value of the SamplesPerBuffer parameter decreases latency and it may increase CPU usage. Increasing value of the SamplesPerBuffer parameter increases latency and it may decrease CPU usage.


CohStopDDC1

Stops DDC1 streaming on all the devices of the device set.

C/C++ declaration

BOOL __stdcall CohStopDDC1(INT32 hDeviceSet);

Address retrieval

COH_G35DDC_STOP_DDC1 CohStopDDC1=(COH_G35DDC_STOP_DDC1)GetProcAddress(hAPI,"CohStopDDC1");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The CohStopDDC1 function stops all the streaming beyond the DDC1 in processing chain (DDC2 and audio streaming in all the devices in the set).

The DDC1StreamCallback callback function is not called after CohStopDDC1 returns.


CohGetDDC2

Retrieves information about current DDC type of the DDC2.

C/C++ declaration

BOOL __stdcall CohGetDDC2(INT32 hDeviceSet,UINT32 *DDCTypeIndex,G3XDDC_DDC_INFO *DDCInfo);

Address retrieval

COH_G35DDC_GET_DDC2 CohGetDDC2=(COH_G35DDC_GET_DDC2)GetProcAddress(hAPI,"CohGetDDC2");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DDCTypeIndex
[out] Pointer to a variable that receives index of current DDC type of the DDC2. This parameter can be NULL if the application does not require this information.
DDCInfo
[out] Pointer to a G3XDDC_DDC_INFO structure to be filled with information about current DDC type of the DDC2. This parameter can be NULL if the application does not require this information.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

DDC type of DDC2 in each device is the same and it depends on DDC type of DDC1, it cannot be changed by the application directly. DDC type of DDC2 is equal to DDC type of DDC1 if DDC type index of DDC1 is less than or equal to 5 (sample rate: 80 kHz, bandwidth: 64 kHz, bits per sample: 32). If DDC type index of DDC1 is above 5, DDC type index of DDC2 is always 5. Changing of DDC type of DDC1 can cause change of DDC type of DDC2, so it is useful to call CohGetDDC2 immediately after the CohSetDDC1 function to determine current DDC type of DDC2 if the application needs to know parameters of DDC2.

The BitsPerSample member of the G3XDDC_DDC_INFO structure is not used and it can be ignored for DDC2. I and Q samples in buffers passed to the DDC2StreamCallback and DDC2PreprocessedStreamCallback DDC2 callback functions are always in IEEE float (32 bit, little endian) format.

Returned DDCTypeIndex can be passed to the CohGetDDCInfo function.


CohSetDDC2Frequency

Sets relative center frequency of DDC2 for specified device of the device set.

C/C++ declaration

BOOL __stdcall CohSetDDC2Frequency(INT32 hDeviceSet,UINT32 DeviceIndex,INT32 Frequency);

Address retrieval

COH_G35DDC_SET_DDC2_FREQUENCY CohSetDDC2Frequency=(COH_G35DDC_SET_DDC2_FREQUENCY)GetProcAddress(hAPI,"CohSetDDC2Frequency");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Frequency
[in] Specifies new center frequency of DDC2 in Hz.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Value of the Frequency parameter is center frequency of the DDC2 relative to center of the DDC1. The value can be negative.

Absolute frequency of the DDC2 is given by the following formula:

faDDC2 = fDDC1 + frDDC2

Where faDDC2 is absolute center frequency of DDC2, fDDC1 is center frequency of the DDC1 in Hz (set using the CohSetDDC1Frequency function) and frDDC2 is relative center frequency of DDC2 in Hz (set using CohSetDDC2Frequency).

Changing of DDC2 relative frequency changes absolute frequency of the DDC2 and demodulator of specified device.

Use the CohGetDDC2Frequency function to determine current relative center frequency of the DDC2.

The following example shows three methods how it is possible to set absolute DDC2 center frequency of the first device (DeviceIndex = 0) to 11.01 MHz:


INT32 hDeviceSet; //Handle to G35DDC device set returned by the CohOpenDeviceSet function



//1. method

CohSetDDC1Frequency(hDeviceSet,11010000);

CohSetDDC2Frequency(hDeviceSet,0,0);



//2. method, it can be used if bandwidth of DDC2 is less than bandwidth of DDC1

CohSetDDC1Frequency(hDeviceSet,11000000);

CohSetDDC2Frequency(hDeviceSet,0,10000);



//3. method, it can be used if bandwidth of DDC2 is less than bandwidth of DDC1

CohSetDDC1Frequency(hDeviceSet,11020000);

CohSetDDC2Frequency(hDeviceSet,0,-10000);


CohGetDDC2Frequency

Retrieves current relative DDC2 center frequency of specified device in the device set.

C/C++ declaration

BOOL __stdcall CohGetDDC2Frequency(INT32 hDeviceSet,UINT32 DeviceIndex,INT32 *Frequency);

Address retrieval

COH_G35DDC_GET_DDC2_FREQUENCY CohGetDDC2Frequency=(COH_G35DDC_GET_DDC2_FREQUENCY)GetProcAddress(hAPI,"CohGetDDC2Frequency");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Frequency
[out] Pointer to a variable that receives current relative center frequency of DDC2 in Hz. The returned value can be negative. See remarks of the CohSetDDC2Frequency for information how to calculate absolute center frequency of DDC2. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohStartDDC2

Starts DDC2 streaming on specified device.

C/C++ declaration

BOOL __stdcall CohStartDDC2(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 SamplesPerBuffer);

Address retrieval

COH_G35DDC_START_DDC2 CohStartDDC2=(COH_G35DDC_START_DDC2)GetProcAddress(hAPI,"CohStartDDC2");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
SamplesPerBuffer
[in] Specifies number of I/Q sample sets in each buffer passed to the the DDC2StreamCallback and DDC2PreprocessedStreamCallback callback functions. The value has to be multiple of 64 greater than zero. If it is zero, the CohStartDDC2 function fails. If it is not multiple of 64 the function rounds it up to nearest multiple of 64.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Before CohStartDDC2 is used, devices of the device set have to be turned on using the CohSetPower function and DDC1 streaming has to be started using the CohStartDDC1 function, otherwise CohStartDDC2 fails.

If the DDC2 streaming for given device is already running, CohStartDDC2 restarts it except the streaming was previously started with the same SamplesPerBuffer parameter. In this case CohStartDDC2 does nothing. Restart of the DDC2 streaming stops audio streaming for give device. CohStartDDC2 does not restart audio streaming.

Use the CohStopDDC2 function to stop DDC2 streaming.

Decreasing value of the SamplesPerBuffer parameter decreases latency and it may increase CPU usage. Increasing value of the SamplesPerBuffer parameter increases latency and it may decrease CPU usage.


CohStopDDC2

Stops DDC2 streaming on specified device.

C/C++ declaration

BOOL __stdcall CohStopDDC2(INT32 hDeviceSet,UINT32 DeviceIndex);

Address retrieval

COH_G35DDC_STOP_DDC2 CohStopDDC2=(COH_G35DDC_STOP_DDC2)GetProcAddress(hAPI,"CohStopDDC2");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If audio streaming for given device is running, it is stopped too.

If DDC2 streaming is not active, CohStopDDC2 does nothing.

The DDC2StreamCallback and DDC2PreprocessedStreamCallback callback functions are not called when CohStopDDC2 returns.


CohSetDDC2NoiseBlanker

Enables or disables noise blanker on DDC2 stream of specified device.

C/C++ declaration

BOOL __stdcall CohSetDDC2NoiseBlanker(INT32 hDeviceSet,UINT32 DeviceIndex,BOOL Enabled);

Address retrieval

COH_G35DDC_SET_DDC2_NOISE_BLANKER CohSetDDC2NoiseBlanker=(COH_G35DDC_SET_DDC2_NOISE_BLANKER)GetProcAddress(hAPI,"CohSetDDC2NoiseBlanker");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Enabled
[in] Specifies whether to enable or disable noise blanker. If this parameter is non-zero, noise blanker is enabled. If the parameter is zero, noise blanker is disabled.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetDDC2NoiseBlanker function to determine current state of the noise blanker.

CohGetDDC2NoiseBlanker

Retrieves current DDC2 noise blanker state of specified device.

C/C++ declaration

BOOL __stdcall CohGetDDC2NoiseBlanker(INT32 hDeviceSet,UINT32 DeviceIndex,BOOL *Enabled);

Address retrieval

COH_G35DDC_GET_DDC2_NOISE_BLANKER CohGetDDC2NoiseBlanker=(COH_G35DDC_GET_DDC2_NOISE_BLANKER)GetProcAddress(hAPI,"CohGetDDC2NoiseBlanker");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Enabled
[out] Pointer to a variable that receives current state of noise blanker. The value is non-zero if noise blanker is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDDC2NoiseBlankerThreshold

Specifies DDC2 noise blanker threshold of specified device.

C/C++ declaration

BOOL __stdcall CohSetDDC2NoiseBlankerThreshold(INT32 hDeviceSet,UINT32 DeviceIndex,double Threshold);

Address retrieval

COH_G35DDC_SET_DDC2_NOISE_BLANKER_THRESHOLD CohSetDDC2NoiseBlankerThreshold=

    (COH_G35DDC_SET_DDC2_NOISE_BLANKER_THRESHOLD)GetProcAddress(hAPI,"CohSetDDC2NoiseBlankerThreshold");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Threshold
[in] Specifies threshold in %.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetDDC2NoiseBlankerThreshold function to retrieve current threshold of the noise blanker.

CohGetDDC2NoiseBlankerThreshold

Retrieves DDC2 noise blanker threshold of specified device.

C/C++ declaration

BOOL __stdcall CohGetDDC2NoiseBlankerThreshold(INT32 hDeviceSet,UINT32 DeviceIndex,double *Threshold);

Address retrieval

COH_G35DDC_GET_DDC2_NOISE_BLANKER_THRESHOLD CohGetDDC2NoiseBlankerThreshold=

    (COH_G35DDC_GET_DDC2_NOISE_BLANKER_THRESHOLD)GetProcAddress(hAPI,"CohGetDDC2NoiseBlankerThreshold");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Threshold
[out] Pointer to a variable that receives threshold of the noise blanker. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetDDC2NoiseBlankerExcessValue

Determines value which indicates percentage ratio between short time average signal level and maximum level.

C/C++ declaration

BOOL __stdcall CohGetDDC2NoiseBlankerExcessValue(INT32 hDeviceSet,UINT32 DeviceIndex,double *Value);

Address retrieval

COH_G35DDC_GET_DDC2_NOISE_BLANKER_EXCESS_VALUE CohGetDDC2NoiseBlankerExcessValue=

    (COH_G35DDC_GET_DDC2_NOISE_BLANKER_EXCESS_VALUE)GetProcAddress(hAPI,"CohGetDDC2NoiseBlankerExcessValue");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Value
[out] Pointer to a variable that receives current excess value in %. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetSignalLevel

Determines current signal level for specified device.

C/C++ declaration

BOOL __stdcall CohGetSignalLevel(INT32 hDeviceSet,UINT32 DeviceIndex,FLOAT *Peak,FLOAT *RMS);

Address retrieval

COH_G35DDC_GET_SIGNAL_LEVEL CohGetSignalLevel=(COH_G35DDC_GET_SIGNAL_LEVEL)GetProcAddress(hAPI,"CohGetSignalLevel");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Peak
[out] Pointer to a variable that receives current signal level (peak) in Volts. This parameter can be NULL if the application does not require this information.
RMS
[out] Pointer to a variable that receives current signal level (RMS) in Volts. This parameter can be NULL if the application does not require this information.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

DDC2 streaming has to be active (started using the CohStartDDC2 function) before calling of CohGetSignalLevel, otherwise returned peak and RMS signal levels are zero.

Signal level is evaluated from signal after the demodulator filter and before the notch filter (see block diagram), the signal is selected by the demodulator filter.

Signal level is evaluated for each buffer that processed by the demoduletor filter. Buffer size (signal level evaluation rate) is given by the SamplesPerBuffer parameter of the CohStartDDC2 function.

The DDC2PreprocessedStreamCallback callback function provides signal level for each buffer passed the callback, i.e. for each buffer used in signal level evaluation. This provides way to get signal level from each processed buffer without need of pulling it using CohGetSignalLevel.

To convert RMS signal level in Volts to power in dBm use the following formulas:

P[W] = (VRMS)2 / R = (VRMS)2 / 50

P[dBm]= 10 * log10( P[W] * 1000 )

Where VRMS is RMS signal level in Volts obtained by CohGetSignalLevel, R is G35DDC receiver input impedance (50 Ω), P[W] is power in Watts, P[dBm] is power in dBm and 1000 is conversion coefficient W -> mW.

The following example shows how to obtain current signal level in dBm from device 0:


#include <stdio.h>

#include <math.h>



INT32 hDeviceSet; //handle to G35DDC device set returned by the CohOpenDeviceSet function

float P_dBm,V_RMS;



CohGetSignalLevel(hDeviceSet,0,NULL,&V_RMS);



P_dBm=10.0*log10(V_RMS*V_RMS*(1000.0/50.0));



printf("Current signal level [RMS]: %.1f dBm\n",P_dBm);


CohSetNotchFilter

Enables or disables notch filter of specified device.

C/C++ declaration

BOOL __stdcall CohSetNotchFilter(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 NotchFilterIndex,BOOL Enabled);

Address retrieval

COH_G35DDC_SET_NOTCH_FILTER CohSetNotchFilter=(COH_G35DDC_SET_NOTCH_FILTER)GetProcAddress(hAPI,"CohSetNotchFilter");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Enabled
[in] Specifies whether to enable or disable notch filter. If this parameter is non-zero, the filter is enabled. If the parameter is zero, the filter is disabled.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetNotchFilter function to determine whether the filter is enabled or disabled.

CohGetNotchFilter

Retrieves current notch filter state of specified device.

C/C++ declaration

BOOL __stdcall CohGetNotchFilter(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 NotchFilterIndex,BOOL *Enabled);

Address retrieval

COH_G35DDC_GET_NOTCH_FILTER CohGetNotchFilter=(COH_G35DDC_GET_NOTCH_FILTER)GetProcAddress(hAPI,"CohGetNotchFilter");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Enabled
[out] Pointer to a variable that receives current state of the notch filter. The value is non-zero if the filter is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetNotchFilterFrequency

Specifies relative center frequency of the notch filter for specified device.

C/C++ declaration

BOOL __stdcall CohSetNotchFilterFrequency(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 NotchFilterIndex,INT32 Frequency);

Address retrieval

COH_G35DDC_SET_NOTCH_FILTER_FREQUENCY CohSetNotchFilterFrequency=

        (COH_G35DDC_SET_NOTCH_FILTER_FREQUENCY)GetProcAddress(hAPI,"CohSetNotchFilterFrequency");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Frequency
[in] Specifies new center frequency of the notch filter in Hz.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Value of the Frequency parameter is new center frequency of the notch filter relative to center of the DDC2 (see the CohSetDDC2Frequency function). The value can be negative.

Use the CohGetNotchFilterFrequency function to retrieve current center frequency of the notch filter.


CohGetNotchFilterFrequency

Retrieves current relative center frequency of the notch filter.

C/C++ declaration

BOOL __stdcall CohGetNotchFilterFrequency(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 NotchFilterIndex,INT32 *Frequency);

Address retrieval

G35DDC_GET_NOTCH_FILTER_FREQUENCY CohGetNotchFilterFrequency=

        (G35DDC_GET_NOTCH_FILTER_FREQUENCY)GetProcAddress(hAPI,"CohGetNotchFilterFrequency");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Frequency
[out] Pointer to a variable that receives current center frequency of the notch filter. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetNotchFilterBandwidth

Specifies bandwidth of the notch filter of specified device.

C/C++ declaration

BOOL __stdcall CohSetNotchFilterBandwidth(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 NotchFilterIndex,UINT32 Bandwidth);

Address retrieval

COH_G35DDC_SET_NOTCH_FILTER_BANDWIDTH CohSetNotchFilterBandwidth=

        (COH_G35DDC_SET_NOTCH_FILTER_BANDWIDTH)GetProcAddress(hAPI,"CohSetNotchFilterBandwidth");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Bandwidth
[in] Specifies new bandwidth of the notch filter in Hz. The bandwidth can be from range 1 - 3000 Hz.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetNotchFilterBandwidth function to retrieve current bandwidth of the notch filter.


CohGetNotchFilterBandwidth

Retrieves current bandwidth of the notch filter for specified device.

C/C++ declaration

BOOL __stdcall CohGetNotchFilterBandwidth(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 NotchFilterIndex,UINT32 *Bandwidth);

Address retrieval

COH_G35DDC_GET_NOTCH_FILTER_BANDWIDTH CohGetNotchFilterBandwidth=

        (COH_G35DDC_GET_NOTCH_FILTER_BANDWIDTH)GetProcAddress(hAPI,"CohGetNotchFilterBandwidth");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Bandwidth
[out] Pointer to a variable that receives current bandwidth of the notch filter. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetNotchFilterLength

Specifies notch filter length for specified device. The notch filter is implemented as FIR filter. This function specifies number of coefficients used in filtration procedure.

C/C++ declaration

BOOL __stdcall CohSetNotchFilterLength(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 NotchFilterIndex,UINT32 Length);

Address retrieval

G35DDC_SET_NOTCH_FILTER_LENGTH CohSetNotchFilterLength=

        (G35DDC_SET_NOTCH_FILTER_LENGTH)GetProcAddress(hAPI,"CohSetNotchFilterLength");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Length
[in] Specifies length of the notch filter. The value has to be multiple of 64, greater than or equal to 64 and less than or equal to 32768. If it is not multiple of 64 the function rounds it up to nearest multiple of 64.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Increasing the filter length increases filter steepness and it may increase CPU usage.

Use the CohGetNotchFilterLength function to determine current length of the notch filter.


CohGetNotchFilterLength

Retrieves current notch filter length of specified device.

C/C++ declaration

BOOL __stdcall CohGetNotchFilterLength(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 NotchFilterIndex,UINT32 *Length);

Address retrieval

COH_G35DDC_GET_NOTCH_FILTER_LENGTH CohGetNotchFilterLength=

        (COH_G35DDC_GET_NOTCH_FILTER_LENGTH)GetProcAddress(hAPI,"CohGetNotchFilterLength");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Length
[out] Pointer to a variable that receives current length of the notch filter. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetAGC

Enables or disables AGC for specified device.

C/C++ declaration

BOOL __stdcall CohSetAGC(INT32 hDeviceSet,UINT32 DeviceIndex,BOOL Enabled);

Address retrieval

COH_G35DDC_SET_AGC CohSetAGC=(COH_G35DDC_SET_AGC)GetProcAddress(hAPI,"CohSetAGC");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Enabled
[in] Specifies whether to enable or disable AGC. If this parameter is non-zero, the AGC is enabled. If the parameter is zero, the AGC is disabled.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If the AGC is disabled, the signal is affected by fixed gain specified using the CohSetGain function.

Use the CohGetAGC function to determine current state of the AGC.


CohGetAGC

Retrieves current state of the AGC for specified device.

C/C++ declaration

BOOL __stdcall CohGetAGC(INT32 hDeviceSet,UINT32 DeviceIndex,BOOL *Enabled);

Address retrieval

COH_G35DDC_GET_AGC CohGetAGC=(COH_G35DDC_GET_AGC)GetProcAddress(hAPI,"CohGetAGC");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Enabled
[out] Pointer to a variable that receives current state of the AGC. The value is non-zero if the AGC is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetAGCParams

Sets parameters of the AGC of specified device.

C/C++ declaration

BOOL __stdcall CohSetAGCParams(INT32 hDeviceSet,UINT32 DeviceIndex,double AttackTime,double DecayTime,double ReferenceLevel);

Address retrieval

COH_G35DDC_SET_AGC_PARAMS CohSetAGCParams=(COH_G35DDC_SET_AGC_PARAMS)GetProcAddress(hAPI,"CohSetAGCParams");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
AttackTime
[in] Specifies new attack time of the AGC in seconds.
DecayTime
[in] Specifies new decay time of the AGC in seconds.
ReferenceLevel
[in] Specifies new reference level of the AGC in dB.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetAGCParams function to determine current parameters of the AGC.


CohGetAGCParams

Retrieves current parameters of the AGC for specified device.

C/C++ declaration

BOOL __stdcall CohGetAGCParams(INT32 hDeviceSet,UINT32 DeviceIndex,double *AttackTime,double *DecayTime,double *ReferenceLevel);

Address retrieval

COH_G35DDC_GET_AGC_PARAMS CohGetAGCParams=(COH_G35DDC_GET_AGC_PARAMS)GetProcAddress(hAPI,"CohGetAGCParams");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
AttackTime
[out] Pointer to a variable that receives current attack time of the AGC in seconds. This parameter can be NULL if the application does not require this information.
DecayTime
[out] Pointer to a variable that receives current decay time of the AGC in seconds. This parameter can be NULL if the application does not require this information.
ReferenceLevel
[out] Pointer to a variable that receives current reference level of the AGC in dB. This parameter can be NULL if the application does not require this information.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetMaxAGCGain

Sets maximum gain of the AGC for specified device.

C/C++ declaration

BOOL __stdcall CohSetMaxAGCGain(INT32 hDeviceSet,UINT32 DeviceIndex,double MaxGain);

Address retrieval

COH_G35DDC_SET_MAX_AGC_GAIN CohSetMaxAGCGain=(COH_G35DDC_SET_MAX_AGC_GAIN)GetProcAddress(hAPI,"CohSetMaxAGCGain");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
MaxGain
[in] Specifies new maximum gain of the AGC in dB.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetMaxAGCGain function to determine maximum gain of the AGC.


CohGetMaxAGCGain

Retrieves current maximum gain of the AGC of specified device.

C/C++ declaration

BOOL __stdcall CohGetMaxAGCGain(INT32 hDeviceSet,UINT32 DeviceIndex,double *MaxGain);

Address retrieval

COH_G35DDC_GET_MAX_AGC_GAIN CohGetMaxAGCGain=(COH_G35DDC_GET_MAX_AGC_GAIN)GetProcAddress(hAPI,"CohGetMaxAGCGain");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
MaxGain
[out] Pointer to a variable that receives current maximum gain of the AGC in dB. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetGain

Sets fixed gain for specified device. This gain is applied to I/Q signal if the AGC is disabled, otherwise it is not used.

C/C++ declaration

BOOL __stdcall CohSetGain(INT32 hDeviceSet,UINT32 DeviceIndex,double Gain);

Address retrieval

COH_G35DDC_SET_GAIN CohSetGain=(COH_G35DDC_SET_GAIN)GetProcAddress(hAPI,"CohSetGain");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Gain
[in] Specifies new fixed gain in dB.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetGain function to determine current fixed gain.


CohGetGain

Retrieves current fixed gain of specified device.

C/C++ declaration

BOOL __stdcall CohGetGain(INT32 hDeviceSet,UINT32 DeviceIndex,double *Gain);

Address retrieval

COH_G35DDC_GET_GAIN CohGetGain=(COH_G35DDC_GET_GAIN)GetProcAddress(hAPI,"CohGetGain");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Gain
[out] Pointer to a variable that receives current fixed gain in dB. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetCurrentGain

Retrieves current gain that is applied to I/Q signal of specified device.

C/C++ declaration

BOOL __stdcall CohGetCurrentGain(INT32 hDeviceSet,UINT32 DeviceIndex,double *CurrentGain);

Address retrieval

COH_G35DDC_GET_CURRENT_GAIN CohGetCurrentGain=(COH_G35DDC_GET_CURRENT_GAIN)GetProcAddress(hAPI,"CohGetCurrentGain");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
CurrentGain
[out] Pointer to a variable that receives current gain in dB. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If the AGC is enabled (using the CohSetAGC function), the variable pointed to by the CurrentGain parameter is filled by current gain of the AGC. If the AGC is disabled, the variable pointed to by the CurrentGain parameter is filled by fixed gain that is specified using the CohSetGain function.

CohSetDemodulatorFilterBandwidth

Sets bandwidth of the demodulator filter of specified device.

C/C++ declaration

BOOL __stdcall CohSetDemodulatorFilterBandwidth(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 Bandwidth);

Address retrieval

COH_G35DDC_SET_DEMODULATOR_FILTER_BANDWIDTH CohSetDemodulatorFilterBandwidth=

    (COH_G35DDC_SET_DEMODULATOR_FILTER_BANDWIDTH)GetProcAddress(hAPI,"CohSetDemodulatorFilterBandwidth");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Bandwidth
[in] Specified new bandwidth of the demodulator filter in Hz. Possible values are from range 1 Hz to current DDC2 bandwidth. Use the CohGetDDC2 function to retrieve information about current DDC type of DDC2.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The demodulator filter bandwidth can be changed using the CohSetDDC1 function. It can change DDC type of DDC2 and if the current demodulator filter bandwidth is greater than new bandwidth of DDC2, the demodulator filter bandwidth is reduced. So it is useful to call the CohGetDemodulatorFilterBandwidth function immediately after CohSetDDC1.

CohGetDemodulatorFilterBandwidth

Retrieves current demodulator filter bandwidth of specified device.

C/C++ declaration

BOOL __stdcall CohGetDemodulatorFilterBandwidth(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 *Bandwidth);

Address retrieval

COH_G35DDC_GET_DEMODULATOR_FILTER_BANDWIDTH CohGetDemodulatorFilterBandwidth=

    (COH_G35DDC_GET_DEMODULATOR_FILTER_BANDWIDTH)GetProcAddress(hAPI,"CohGetDemodulatorFilterBandwidth");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Bandwidth
[out] Pointer to a variable that receives current demodulator filter bandwidth. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDemodulatorFilterShift

Sets demodulator filter shift of specified device.

C/C++ declaration

BOOL __stdcall CohSetDemodulatorFilterShift(INT32 hDeviceSet,UINT32 DeviceIndex,INT32 Shift);

Address retrieval

COH_G35DDC_SET_DEMODULATOR_FILTER_SHIFT CohSetDemodulatorFilterShift=

    (COH_G35DDC_SET_DEMODULATOR_FILTER_SHIFT)GetProcAddress(hAPI,"CohSetDemodulatorFilterShift");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Shift
[in] Specified new shift of the demodulator filter in Hz.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Value of the Shift parameter is shift in Hz relative to center of the demodulator. This value can be negative.

This function does not change demodulator frequency just shift the filter from demodulator's centre.

Use the CohGetDemodulatorFilterShift function to determine current demodulator filter shift.


CohGetDemodulatorFilterShift

Retrieves current shift of the demodulator filter for specified device.

C/C++ declaration

BOOL __stdcall CohGetDemodulatorFilterShift(INT32 hDeviceSet,UINT32 DeviceIndex,INT32 *Shift);

Address retrieval

COH_G35DDC_GET_DEMODULATOR_FILTER_SHIFT CohGetDemodulatorFilterShift=

    (COH_G35DDC_GET_DEMODULATOR_FILTER_SHIFT)GetProcAddress(hAPI,"CohGetDemodulatorFilterShift");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Shift
[out] Pointer to a variable that receives current shift of the demodulator. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDemodulatorFilterLength

Specifies demodulator filter length of specified device. The demodulator filter is implemented as FIR filter. This function specifies number of coefficients used in filtration procedure.

C/C++ declaration

BOOL __stdcall CohSetDemodulatorFilterLength(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 Length);

Address retrieval

COH_G35DDC_SET_DEMODULATOR_FILTER_LENGTH CohSetDemodulatorFilterLength=

    (COH_G35DDC_SET_DEMODULATOR_FILTER_LENGTH)GetProcAddress(hAPI,"CohSetDemodulatorFilterLength");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Length
[in] Specifies length of the demodulator filter. The value has to be multiple of 64, greater than or equal to 64 and less than or equal to 32768. If it is not multiple of 64 the function rounds it up to nearest multiple of 64.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Increasing the filter length increases filter steepness and it may increase CPU usage.

Use the CohGetDemodulatorFilterLength function to determine current length of the demodulator filter.


CohGetDemodulatorFilterLength

Retrieves current length of the demodulator filter for specified device.

C/C++ declaration

BOOL __stdcall CohGetDemodulatorFilterLength(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 *Length);

Address retrieval

COH_G35DDC_GET_DEMODULATOR_FILTER_LENGTH CohGetDemodulatorFilterLength=

    (COH_G35DDC_GET_DEMODULATOR_FILTER_LENGTH)GetProcAddress(hAPI,"CohGetDemodulatorFilterLength");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Length
[out] Pointer to a variable that receives current demodulator filter length. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDemodulatorMode

Sets demodulator mode of specified device.

C/C++ declaration

BOOL __stdcall CohSetDemodulatorMode(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 Mode);

Address retrieval

COH_G35DDC_SET_DEMODULATOR_MODE CohSetDemodulatorMode=(COH_G35DDC_SET_DEMODULATOR_MODE)GetProcAddress(hAPI,"CohSetDemodulatorMode");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Mode
[in] Specifies new demodulator mode. This value can be one of the following:

ValueMeaning
G3XDDC_MODE_CWContinuous wave
G3XDDC_MODE_AMAmplitude modulation
G3XDDC_MODE_FMFrequency modulation
G3XDDC_MODE_LSBLower sideband modulation
G3XDDC_MODE_USBUpper sideband modulation
G3XDDC_MODE_AMSAmplitude modulation
G3XDDC_MODE_DSBDouble sideband modulation
G3XDDC_MODE_ISBIndependent sideband modulation
G3XDDC_MODE_DRMDigital Radio Mondiale

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

DRM demodulation is only available if valid DRM key is loaded using the CohSetDRMKey function. More information about obtaining DRM key at http://www.winradio.com/home/drm.htm.

Use the CohGetDemodulatorMode function to retrieve current demodulator mode.


CohGetDemodulatorMode

Retrieves current demodulator mode of specified device.

C/C++ declaration

BOOL __stdcall CohGetDemodulatorMode(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 *Mode);

Address retrieval

COH_G35DDC_GET_DEMODULATOR_MODE CohGetDemodulatorMode=(COH_G35DDC_GET_DEMODULATOR_MODE)GetProcAddress(hAPI,"CohGetDemodulatorMode");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Mode
[out] Pointer to a variable that receives current demodulator mode. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDemodulatorFrequency

Sets relative center frequency of demodulator for specified device.

C/C++ declaration

BOOL __stdcall CohSetDemodulatorFrequency(INT32 hDeviceSet,UINT32 DeviceIndex,INT32 Frequency);

Address retrieval

COH_G35DDC_SET_DEMODULATOR_FREQUENCY CohSetDemodulatorFrequency=

    (COH_G35DDC_SET_DEMODULATOR_FREQUENCY)GetProcAddress(hAPI,"CohSetDemodulatorFrequency");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Frequency
[in] Specified new center frequency of the demodulator in Hz.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Value of the Frequency parameter is center frequency of the demodulator relative to center of the DDC2. The value can be negative.

Absolute frequency of the demodulator is given by the following formula:

faDEM = fDDC1 + frDDC2 + frDEM

Where faDEM is absolute center frequency of the demodulator in Hz, fDDC1 is center frequency of the DDC1 in Hz (set using the CohSetDDC1Frequency function), frDDC2 is relative center frequency of DDC2 of in Hz (set using the CohSetDDC2Frequency) and frDEM is relative center frequency of the demodulator in Hz (set using CohSetDemodulatorFrequency).

Absolute center frequency of the demodulator is the real-world frequency that you are listening to.

Use the CohGetDemodulatorFrequency function to determine current relative center frequency of the demodulator for given device.

The following example shows four methods how it is possible to set absolute demodulator center frequency of device 0 to 11.01 MHz:


INT32 hDeviceSet; //Handle to G35DDC device set returned by the CohOpenDeviceSet function



//1. method

CohSetDDC1Frequency(hDeviceSet,11010000);

CohSetDDC2Frequency(hDeviceSet,0,0);

CohSetDemodulatorFrequency(hDeviceSet,0,0);



//2. method

CohSetDDC1Frequency(hDeviceSet,11000000);

CohSetDDC2Frequency(hDeviceSet,0,10000);

CohSetDemodulatorFrequency(hDeviceSet,0,0);



//3. method

CohSetDDC1Frequency(hDeviceSet,11020000);

CohSetDDC2Frequency(hDeviceSet,0,-5000);

CohSetDemodulatorFrequency(hDeviceSet,0,-5000);



//4. method

CohSetFrequency(hDeviceSet,0,11010000); 

//The CohSetFrequency function sets DDC1, DDC2 and demodulator

//center frequencies so that demodulator's absolute frequency is set to the required frequency


CohGetDemodulatorFrequency

Retrieves current relative center frequency of the demodulator for specified device.

C/C++ declaration

BOOL __stdcall CohGetDemodulatorFrequency(INT32 hDeviceSet,UINT32 DeviceIndex,INT32 *Frequency);

Address retrieval

COH_G35DDC_GET_DEMODULATOR_FREQUENCY CohGetDemodulatorFrequency=

    (COH_G35DDC_GET_DEMODULATOR_FREQUENCY)GetProcAddress(hAPI,"CohGetDemodulatorFrequency");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Frequency
[out] Pointer to a variable that receives current center frequency of the demodulator. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDemodulatorParam

Sets a parameter of demodulation of specified device.

C/C++ declaration

BOOL __stdcall CohSetDemodulatorParam(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 Code,CONST VOID *Buffer,UINT32 BufferSize);

Address retrieval

COH_G35DDC_SET_DEMODULATOR_PARAM CohSetDemodulatorParam=

    (COH_G35DDC_SET_DEMODULATOR_PARAM)GetProcAddress(hAPI,"CohSetDemodulatorParam");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Code
[in] Specifies code of the demodulator parameter to be set by the function. The code can be one of the following:

ValueMeaning
G3XDDC_DEMODULATOR_PARAM_AMS_SIDE_BAND

Side band for synchronous AM demodulation.

The Buffer parameter has to be pointer to an UINT32 variable, and the BufferSize parameter has to be sizeof(UINT32).

Value of the variable pointed to by the Buffer parameter can be one of the following:

G3XDDC_SIDE_BAND_LOWER
AMS demodulator will use lower sideband

G3XDDC_SIDE_BAND_UPPER
AMS demodulator will use upper sideband

G3XDDC_SIDE_BAND_BOTH
AMS demodulator will use both side bands.

G3XDDC_DEMODULATOR_PARAM_AMS_CAPTURE_RANGE

Capture range of synchronous AM demodulator.

The Buffer parameter has to be pointer to a G3XDDC_AMS_CAPTURE_RANGE structure, and the BufferSize parameter has to be sizeof(G3XDDC_AMS_CAPTURE_RANGE).

G3XDDC_DEMODULATOR_PARAM_CW_FREQUENCY

CW tone frequency

The Buffer parameter has to be pointer to a INT32 variable, and the BufferSize parameter has to be sizeof(INT32).

Value of the variable pointed to by the Buffer parameter is CW tone frequency in Hz.

G3XDDC_DEMODULATOR_PARAM_DSB_SIDE_BAND

Side band for DSB demodulation.

The Buffer parameter has to be pointer to an UINT32 variable, and the BufferSize parameter has to be sizeof(UINT32).

Value of the variable pointed to by the Buffer parameter can be one of the following:

G3XDDC_SIDE_BAND_LOWER
DSB demodulator will use lower sideband

G3XDDC_SIDE_BAND_UPPER
DSB demodulator will use upper sideband

G3XDDC_SIDE_BAND_BOTH
DSB demodulator will use both side bands.

G3XDDC_DEMODULATOR_PARAM_ISB_SIDE_BAND

Side band for ISB demodulation.

The Buffer parameter has to be pointer to an UINT32 variable, and the BufferSize parameter has to be sizeof(UINT32).

Value of the variable pointed to by the Buffer parameter can be one of the following:

G3XDDC_SIDE_BAND_LOWER
ISB demodulator will use lower sideband

G3XDDC_SIDE_BAND_UPPER
ISB demodulator will use upper sideband

G3XDDC_SIDE_BAND_BOTH
ISB demodulator will use both side bands.

G3XDDC_DEMODULATOR_PARAM_DRM_AUDIO_SERVICE

Audio service of DRM demodulator/decoder to be listening to.

The Buffer parameter has to be pointer to an UINT32 variable, and the BufferSize parameter has to be sizeof(UINT32).

Value of the variable pointed to by the Buffer parameter is index of the audio service. Possible values are: 1, 2, 3, 4, where 1 is the first audio service, 2 is the second one, etc. Use the CohGetDemodulatorState function with G3XDDC_DEMODULATOR_STATE_DRM_STATUS to retrieve information about available audio services for currently received DRM station.

G3XDDC_DEMODULATOR_PARAM_DRM_MULTIMEDIA_SERVICE

Multimedia service of DRM demodulator/decoder to be decoded.

The Buffer parameter has to be pointer to an UINT32 variable, and the BufferSize parameter has to be sizeof(UINT32).

Value of the variable pointed to by the Buffer parameter is index of the multimedia service. Possible values are: 1, 2, 3, 4, where 1 is the first audio service, 2 is the second one, etc. Use the CohGetDemodulatorState function with G3XDDC_DEMODULATOR_STATE_DRM_STATUS to retrieve information about available multimedia services for currently received DRM station.

It is required that DRM multimedia player has to be installed to display multimedia content. It is included in G35DDC software installer as optional.

Buffer
[in] Pointer to a buffer containing value of the demodulator parameter the function will set. This parameter cannot be NULL.
BufferSize
[in] Specifies the size of the buffer.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetDemodulatorParam

Retrieves a parameter of demodulation of specified device.

C/C++ declaration

BOOL __stdcall CohGetDemodulatorParam(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 Code,VOID *Buffer,UINT32 BufferSize);

Address retrieval

COH_G35DDC_GET_DEMODULATOR_PARAM CohGetDemodulatorParam=

    (COH_G35DDC_GET_DEMODULATOR_PARAM)GetProcAddress(hAPI,"CohGetDemodulatorParam");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Code
[in] Specifies code of the demodulator parameter to be retrieved. For detailed information about available codes see SetDemodulatorParam.
Buffer
[out] Pointer to a buffer that receives requested parameter. This parameter cannot be NULL.
BufferSize
[in] Specifies the size of the buffer.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetDemodulatorState

Retrieves information about current demodulator state of specified device.

C/C++ declaration

BOOL __stdcall CohGetDemodulatorState(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 Code,VOID *Buffer,UINT32 BufferSize);

Address retrieval

COH_G35DDC_GET_DEMODULATOR_STATE CohGetDemodulatorState=

    (COH_G35DDC_GET_DEMODULATOR_STATE)GetProcAddress(hAPI,"CohGetDemodulatorState");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Code
[in] Specifies code of the demodulator state to be retrieved. It can be one of the following:

ValueMeaning
G3XDDC_DEMODULATOR_STATE_AMS_LOCK

Lock state of synchronous AM demodulation.

The Buffer parameter has to be pointer to a BOOL variable, and the BufferSize parameter has to be sizeof(BOOL).

Received value is non-zero if synchronous AM demodulator is locked to signal, and zero if it is not locked.

G3XDDC_DEMODULATOR_STATE_AMS_FREQUENCY

Frequency in Hz which synchronous AM demodulator is locked to. It is relative to center of the demodulator. It can be negative.

The Buffer parameter has to be pointer to a double variable, and the BufferSize parameter has to be sizeof(double).

G3XDDC_DEMODULATOR_STATE_AM_DEPTH

Depth of AM modulation in %.

The Buffer parameter has to be pointer to a double variable, and the BufferSize parameter has to be sizeof(double).

G3XDDC_DEMODULATOR_STATE_DSB_LOCK

Lock state of DSB demodulation.

The Buffer parameter has to be pointer to a BOOL variable, and the BufferSize parameter has to be sizeof(BOOL).

Received value is non-zero if DSB demodulator is locked to signal, and zero if it is not locked.

G3XDDC_DEMODULATOR_STATE_DSB_FREQUENCY

Frequency in Hz which DSB demodulator is locked to. It is relative to center of the demodulator. It can be negative.

The Buffer parameter has to be pointer to a double variable, and the BufferSize parameter has to be sizeof(double).

G3XDDC_DEMODULATOR_STATE_TUNE_ERROR

Estimated tune error in Hz.

The Buffer parameter has to be pointer to an INT32 variable, and the BufferSize parameter has to be sizeof(INT32).

Received value is difference between demodulator frequency and frequency of received signal. Subtract the returned tune error from demodulator frequency to get frequency of the received signal. Tune error is relative to center of the demodulator and it can be negative.

G3XDDC_DEMODULATOR_STATE_DRM_STATUS

Status of DRM demodulator/decoder.

The Buffer parameter has to be pointer to a G3XDDC_DRM_STATUS structure, and the BufferSize parameter has to be sizeof(G3XDDC_DRM_STATUS).

G3XDDC_DEMODULATOR_STATE_FM_DEVIATION

Estimated frequency deviation in Hz.

The Buffer parameter has to be pointer to an UINT32 variable, and the BufferSize parameter has to be sizeof(UINT32).

Buffer
[out] Pointer to a buffer that receives requested information. This parameter cannot be NULL.
BufferSize
[in] Specifies the size of the buffer.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohStartAudio

Starts audio streaming for specified device.

C/C++ declaration

BOOL __stdcall CohStartAudio(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 SamplesPerBuffer);

Address retrieval

COH_G35DDC_START_AUDIO CohStartAudio=(COH_G35DDC_START_AUDIO)GetProcAddress(hAPI,"CohStartAudio");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
SamplesPerBuffer
[in] Specifies number of samples in each buffer passed to the the AudioStreamCallback callback function. The value has to be multiple of 64 greater than zero. If it is zero, the StartAudio function fails. If it is not multiple of 64 the function rounds it up to nearest multiple of 64.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Before CohStartAudio is used, the G35DDC devices have to be turned on using the CohSetPower function, DDC1 streaming has to be started using the CohStartDDC1 and DDC2 streaming has to be started using the CohStartDDC2 function, otherwise CohStartAudio fails.

If the audio streaming of specified device is already running, CohStartAudio restarts it except the streaming was previously started with the same SamplesPerBuffer parameter. In this case CohStartAudio does nothing.

Use the CohStopAudio function to stop audio streaming.

Decreasing value of the SamplesPerBuffer parameter decreases latency and it may increase CPU usage. Increasing value of the SamplesPerBuffer parameter increases latency and it may decrease CPU usage.


CohStopAudio

Stops audio streaming for specified device.

C/C++ declaration

BOOL __stdcall CohStopAudio(INT32 hDeviceSet,UINT32 DeviceIndex);

Address retrieval

COH_G35DDC_STOP_AUDIO CohStopAudio=(COH_G35DDC_STOP_AUDIO)GetProcAddress(hAPI,"CohStopAudio");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If audio streaming is not active, CohStopAudio does nothing.

The AudioStreamCallback callback function are not called after CohStopAudio returns.


CohSetAudioGain

Sets fixed audio gain of specified device.

C/C++ declaration

BOOL __stdcall CohSetAudioGain(INT32 hDeviceSet,UINT32 DeviceIndex,double Gain);

Address retrieval

COH_G35DDC_SET_AUDIO_GAIN CohSetAudioGain=(COH_G35DDC_SET_AUDIO_GAIN)GetProcAddress(hAPI,"CohSetAudioGain");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Gain
[in] Specifies new fixed audio gain in dB.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetAudioGain function to retrieve current audio gain.

CohGetAudioGain

Retrieves current fixed audio gain of specified device.

C/C++ declaration

BOOL __stdcall CohGetAudioGain(INT32 hDeviceSet,UINT32 DeviceIndex,double *Gain);

Address retrieval

COH_G35DDC_GET_AUDIO_GAIN CohGetAudioGain=(COH_G35DDC_GET_AUDIO_GAIN)GetProcAddress(hAPI,"CohGetAudioGain");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Gain
[out] Pointer to a variable that receives current fixed gain in dB. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetAudioFilter

Enabled or disables audio filter of device index.

C/C++ declaration

BOOL __stdcall CohSetAudioFilter(INT32 hDeviceSet,UINT32 DeviceIndex,BOOL Enabled);

Address retrieval

COH_G35DDC_SET_AUDIO_FILTER CohSetAudioFilter=(COH_G35DDC_SET_AUDIO_FILTER)GetProcAddress(hAPI,"CohSetAudioFilter");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Enabled
[in] Specifies whether to enable or disable audio filter. If this parameter is non-zero, the filter is enabled. If the parameter is zero, the filter is disabled.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetAudioFiler function to retrieve current state of the audio filter.

CohGetAudioFilter

Retrieves current state of the audio filter for specific device.

C/C++ declaration

BOOL __stdcall CohGetAudioFilter(INT32 hDeviceSet,UINT32 DeviceIndex,BOOL *Enabled);

Address retrieval

COH_G35DDC_GET_AUDIO_FILTER CohGetAudioFilter=(COH_G35DDC_GET_AUDIO_FILTER)GetProcAddress(hAPI,"CohGetAudioFilter");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Enabled
[out] Pointer to a variable that receives current state of the audio filter. The value is non-zero if the filter is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetAudioFilterParams

Sets parameters of the audio filter for specified device.

C/C++ declaration

BOOL __stdcall CohSetAudioFilterParams(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 CutOffLow,UINT32 CutOffHigh,double Deemphasis);

Address retrieval

COH_G35DDC_SET_AUDIO_FILTER_PARAMS CohSetAudioFilterParams=

    (COH_G35DDC_SET_AUDIO_FILTER_PARAMS)GetProcAddress(hAPI,"CohSetAudioFilterParams");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
CutOffLow
[in] Specifies cut-off low frequency of the filter in Hz. This is the start frequency of filter's passband, it can be from range 0 to 23999 Hz. The value has to be less then the cut-off high frequency specified by the CutOffHigh parameter.
CutOffHigh
[in] Specifies cut-off high frequency of the filter in Hz. This is the end frequency of filter's passband it can be from range 1 - 24000 Hz. The value has to be greater than the cut-off low frequency specified by the CutOffLow parameter.
Deemphasis
[in] Specifies de-emphasis the filter in dB per octave. De-emphasis starts at cut-off low frequency of the filter. This value can be from range -9.9 to 0.0 dB/octave. Zero means the de-emphasis is disabled.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Use the CohGetAudioFilerParams function to retrieve current parameters of the audio filter.

CohGetAudioFilterParams

Retrieves current parameters of the audio filter for specified device.

C/C++ declaration

BOOL __stdcall CohGetAudioFilterParams(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 *CutOffLow,UINT32 *CutOffHigh,double *Deemphasis);

Address retrieval

COH_G35DDC_GET_AUDIO_FILTER_PARAMS CohGetAudioFilterParams=

    (COH_G35DDC_GET_AUDIO_FILTER_PARAMS)GetProcAddress(hAPI,"CohGetAudioFilterParams");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
CutOffLow
[out] Pointer to a variable that receives current cut-off low frequency of the filter. This parameter can be NULL if the application does not require this information.
CutOffHigh
[out] Pointer to a variable that receives current cut-off high frequency of the filter. This parameter can be NULL if the application does not require this information.
Deemphasis
[out] Pointer to a variable that receives current de-emphasis setting of the filter. This parameter can be NULL if the application does not require this information.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetAudioFilterLength

Specifies audio filter length of specified device. The audio filter is implemented as FIR filter. This function specifies number of coefficients used in filtration procedure.

C/C++ declaration

BOOL __stdcall CohSetAudioFilterLength(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 Length);

Address retrieval

COH_G35DDC_SET_AUDIO_FILTER_LENGTH CohSetAudioFilterLength=

        (COH_G35DDC_SET_AUDIO_FILTER_LENGTH)GetProcAddress(hAPI,"CohSetAudioFilterLength");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Length
[in] Specifies length of the audio filter. The value has to be multiple of 64, greater than or equal to 64 and less than or equal to 32768. If it is not multiple of 64 the function rounds it up to nearest multiple of 64.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Increasing the filter length increases filter steepness and it may increase CPU usage.

Use the CohGetAudioFilterLength function to determine current length of the audio filter.


CohGetAudioFilterLength

Retrieves current audio filter length of specified device.

C/C++ declaration

BOOL __stdcall CohGetAudioFilterLength(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 *Length);

Address retrieval

COH_G35DDC_GET_AUDIO_FILTER_LENGTH CohGetAudioFilterLength=

        (COH_G35DDC_GET_AUDIO_FILTER_LENGTH)GetProcAddress(hAPI,"CohGetAudioFilterLength");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Length
[out] Pointer to a variable that receives current length of the audio filter. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetVolume

Sets audio volume of specified device.

C/C++ declaration

BOOL __stdcall CohSetVolume(INT32 hDeviceSet,UINT32 DeviceIndex,BYTE Volume);

Address retrieval

COH_G35DDC_SET_VOLUME CohSetVolume=(COH_G35DDC_SET_VOLUME)GetProcAddress(hAPI,"CohSetVolume");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Volume
[in] Specifies new volume. The value can vary from 0 to 31, where 31 means maximum volume.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If the G35DDC receiver has audio output connector (optional), the CohSetVolume function affects the audio signal level at this output (see also CohSetDAC).

Use the CohGetVolume function to retrieve current volume.


CohGetVolume

Retrieve current volume of specified device.

C/C++ declaration

BOOL __stdcall CohGetVolume(INT32 hDeviceSet,UINT32 DeviceIndex,BYTE *Volume);

Address retrieval

COH_G35DDC_GET_VOLUME CohGetVolume=(COH_G35DDC_GET_VOLUME)GetProcAddress(hAPI,"CohGetVolume");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Volume
[out] Pointer to a variable that receives current volume. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetMute

Mutes or unmutes audio of specified device.

C/C++ declaration

BOOL __stdcall CohSetMute(INT32 hDeviceSet,UINT32 DeviceIndex,BOOL Mute);

Address retrieval

COH_G35DDC_SET_MUTE CohSetMute=(COH_G35DDC_SET_MUTE)GetProcAddress(hAPI,"CohSetMute");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Mute
[in] Specifies whether to mute or unmute audio. If this parameter is non-zero, the audio is muted. If the parameter is zero, the audio is unmuted.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If the G35DDC receiver has audio output connector (optional), the CohSetMute function affects the audio signal at this output (see also CohSetDAC).

Use the CohGetMute function to retrieve current mute state.


CohGetMute

Retrieves current mute state of specified device.

C/C++ declaration

BOOL __stdcall CohGetMute(INT32 hDeviceSet,UINT32 DeviceIndex,BOOL *Mute);

Address retrieval

COH_G35DDC_GET_MUTE CohGetMute=(COH_G35DDC_GET_MUTE)GetProcAddress(hAPI,"CohGetMute");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Mute
[out] Pointer to a variable that receives current mute state. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohSetDAC

Allows to route audio output to DAC (Digital-to-analog converter). DAC output is connected to audio output connector of the receiver.

C/C++ declaration

BOOL __stdcall CohSetDAC(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 DAC);

Address retrieval

COH_G35DDC_SET_DAC CohSetDAC=(COH_G35DDC_SET_DAC)GetProcAddress(hAPI,"CohSetDAC");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
DAC
[in] Specifies routed audio to the DAC.

BitMeaning
0If it is set, audio output is routed to left channel of the audio output connector.
1If it is set, audio output is routed to right channel of the audio output connector.
2 - 31Reserved. Must be zero.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The audio output connector is optional. If the receiver does not have audio output connector, CohSetDAC fails. The following example shows how to determine the receive has audio output connector.

    G35DDC_DEVICE_INFO DeviceInfo;

    INT32 hDeviceSet;  //handle to open G35DDC device set

    UINT32 DeviceIndex; //index of device in the device set

    

    CohGetDeviceInfo(hDeviceSet,DeviceIndex,&DeviceInfo);

    

    if(DeviceInfo.Flags & G35DDC_FLAGS_AUDIO_OUTPUT)

    {

        //the receiver has audio output connector

        //route audio output to the audio output connector

        

        CohSetDAC(hDeviceSet,DeviceIndex,0x03);

    }

    else

    {

        //the receiver does not have audio output connector

    }


CohGetDAC

Determines if audio output is routed to audio output connector (DAC).

C/C++ declaration

BOOL __stdcall CohGetDAC(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 *DAC);

Address retrieval

COH_G35DDC_GET_DAC CohGetDAC=(COH_G35DDC_GET_DAC)GetProcAddress(hAPI,"CohGetDAC");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
DAC
[out] Pointer to a variable that receives bitwise array which specifies how the audio is routed to the audio output connector (DAC). For more information, see CohSetDAC. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

CohGetSpectrumCompensation

Determines compensation data for frequency spectrum computed from DDC1, DDC2 and IF signal. It is used to convert relative amplitudes in dB to absolutes ones in dBm.

C/C++ declaration

BOOL __stdcall CohGetSpectrumCompensation(INT32 hDeviceSet,UINT32 DeviceIndex,UINT64 CenterFrequency,UINT32 Width,FLOAT *Buffer,UINT32 Count);

Address retrieval

COH_G35DDC_GET_SPECTRUM_COMPENSATION CohGetSpectrumCompensation=

    (COH_G35DDC_GET_SPECTRUM_COMPENSATION)GetProcAddress(hAPI,"CohGetSpectrumCompensation");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
CenterFrequency
[in] Specifies absolute center frequency of requested compensation data in Hz.
Width
[in] Specifies width of requested compensation data in Hz.
Buffer
[out] Pointer to a buffer to be filled with compensation data. This parameter cannot be NULL.
Count
[in] Specifies number of FLOAT items in the buffer pointed to by the Buffer parameter.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The following example shows how to use the CohGetSpectrumCompensation function in DDC2StreamCallback callback function:




//Let the following is prototype of a function which computes FFT from I/Q signal stored in

//the buffer pointed to be the Input parameter. Result is stored in complex form in the buffer

//pointed to by the Output parameter. Size of the FFT is given be the Size parameter.

//The example uses 2048 bins FFT.

void FFT(float *Output,const float *Input,int Size);



INT32 hDeviceSet; //handle to G35DDC device set

UINT32 AbsDDC2Frequency; //Absolute frequency of the DDC2

INT32 RelDDC2Frequency; //Relative frequency of the DDC2

UINT32 DDC1Frequency; //DDC1 frequency

G3XDDC_DDC_INFO DDC2Info; //Information about current DDC type of the DDC2

FLOAT FFTBuffer[2*2048]; //Buffer for FFT result

FLOAT Compensation[2048]; //Buffer for compensation data

UINT32 FirstBin,LastBin; //the first and last bins in the FFT of useful DDC2 band

G35DDC_CALLBACKS Callbacks; //Structure which contains pointer to callback functions



Code before...



//Retrieve frequency of the DDC1

CohGetDDC1Frequency(hDeviceSet,&DDC1Frequency);



//Retrieve relative frequency of the DDC2 for device 0

CohGetDDC2Frequency(hDeviceSet,0,&RelDDC2Frequency);



//Calculate absolute frequency of the DDC2

AbsDDC2Frequency=(INT32)DDC1Frequency+RelDDC2Frequency;



//Retrieve DDC type information of the DDC2

CohGetDDC2(hDeviceSet,NULL,&DDC2Info);



//Retrieve compensation data for device 0

CohGetSpectrumCompensation(hDeviceSet,0,AbsDDC2Frequency,DDC2Info.SampleRate,Compensation,2048);

//In this case the Width parameter is equal to sample rate, because we need compensation data

//for whole DDC2 band.

//Compensation data have to be updated after change of absolute DDC2 frequency using

//the CohSetDDC1Frequency or CohSetDDC2Frequency function.

//In this case a mutual-exclusion synchronization method (for example critical section) should be used 

//if the Compensation buffer would be modified outside the MyDDC2StreamCallback callback.



FirstBin=2048*(DDC2Info.SampleRate-DDC2Info.Bandwidth)/2/DDC2Info.SampleRate;

LastBin=2048*(DDC2Info.SampleRate+DDC2Info.Bandwidth)/2/DDC2Info.SampleRate;



//Set callback function for DDC2 streaming

//Pointers to callback function which should not be called by the API have to be set to NULL.

Callbacks.DDC2StreamCallback=MyDDC2StreamCallback;



//Start DDC2 streaming for device 0

//The SamplesPerBuffer parameter is set to 2048 which is size of the FFT to simplify

//the example.

CohStartDDC2(hDeviceSet,0,2048);



Code after...

    

void __stdcall MyDDC2StreamCallback(UINT32 DeviceIndex,CONST FLOAT *Buffer,UINT32 NumberOfSamples,DWORD_PTR UserData)

{

 UINT32 i;

 

    //Compute FFT

    FFT(FFTBuffer,Buffer,2048);

    

    //Converts complex FFT result to dB

    for(i=0;i<2048;i++)

    {

        FFTBuffer[i]=(FLOAT)(10.0*log10(FFTBuffer[i*2]*FFTBuffer[i*2]+FFTBuffer[i*2+1]*FFTBuffer[i*2+1]));

    }

    

    //Apply compensation data to get amplitudes in frequency spectrum in dBm

    for(i=0;i<2048;i++)

    {

        FFTBuffer[i]+=Compensation[i];

    }

    

    //now the FFTBuffer contains amplitudes in dBm

    //Useful band starts at the bin given by the FirstBin variable

    //and ends at the bin given by the LastBin variable.

}




CohSetCallbacks

Registers user-defined functions as callback functions called by the API.

C/C++ declaration

BOOL __stdcall CohSetCallbacks(INT32 hDeviceSet,CONST COH_G35DDC_CALLBACKS *Callbacks,DWORD_PTR UserData);

Address retrieval

COH_G35DDC_SET_CALLBACKS CohSetCallbacks=(COH_G35DDC_SET_CALLBACKS)GetProcAddress(hAPI,"CohSetCallbacks");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
Callbacks
[in] Pointer to a COH_G35DDC_CALLBACKS structure which contains pointers to the user-defined function to be registered as callback functions.
UserData
[in] Specifies a user-defined value which is passed to callback functions.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If the application does not require that the API calls some callback function, set related member of the COH_G35DDC_CALLBACKS structure to NULL.

If value of the Callbacks parameter is NULL, all the callback functions are unregistered, the API will not call any callback function.


CohSetDRMKey

Sets directory with DRM key file to unlock DRM demodulator/decoder.

C/C++ declaration

BOOL __stdcall CohSetDRMKey(INT32 hDeviceSet,CONST CHAR *DRMKeyFileDirectory);

Address retrieval

COH_G35DDC_SET_DRM_KEY CohSetDRMKey=(COH_G35DDC_SET_DRM_KEY)GetProcAddress(hAPI,"CohSetDRMKey");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DRMKeyFileDirectory
[in] Pointer to a null-terminated string that specifies the directory which contains valid DRM key file.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If the specfied directory contains valid DRM key file, the key is loaded and the DRM demodulator/decoder is unlocked and available for use, otherwise the function fails.

If the DRM demodulator/decoder is already unlocked, the function does nothing.

Use the CohIsDRMUnlocked function to determine whether DRM demodulator/decoder is unlocked or not.

Information about obtaining DRM key at http://www.winradio.com/home/drm.htm.


CohIsDRMUnlocked

Determines whether DRM demodulator/decoder is unlocked or not.

C/C++ declaration

BOOL __stdcall CohIsDRMUnlocked(INT32 hDeviceSet);

Address retrieval

COH_G35DDC_IS_DRM_UNLOCKED CohIsDRMUnlocked=(COH_G35DDC_IS_DRM_UNLOCKED)GetProcAddress(hAPI,"CohIsDRMUnlocked");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.

Return value

If the function succeeds and the DRM demodulator/decoder is unlocked, the return value is non-zero.
If the function fails or the DRM demodulator/decoder is locked, the return value is zero. To get extended error information, call GetLastError.

CohGetTemperature

Retrieves current internal temperature of the G35DDC device in the device set.

C/C++ declaration

BOOL __stdcall CohGetTemperature(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 *Temperature);

Address retrieval

COH_G35DDC_GET_TEMPERATURE CohGetTemperature=(COH_G35DDC_GET_TEMPERATURE)GetProcAddress(hAPI,"CohGetTemperature");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Temperature
[out] Pointer to a variable that receives current internal temperature in degrees of Celsius. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The G35DDC devices have to be turned on using the CohSetPower function before CohGetTemperature is used. Otherwise CohGetTemperature fails.


CohGetDeviceState

Retrieves current error state of the G35DDC device.

C/C++ declaration

BOOL __stdcall CohGetDeviceState(INT32 hDeviceSet,UINT32 DeviceIndex,UINT32 *State);

Address retrieval

COH_G35DDC_GET_DEVICE_STATE CohGetDeviceState=(COH_G35DDC_GET_DEVICE_STATE)GetProcAddress(hAPI,"CohGetDeviceState");

Parameters

hDeviceSet
[in] Handle to G35DDC device set returned by the CohOpenDeviceSet function.
DeviceIndex
[in] Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
State
[out] Pointer to a variable that receives current error state of the device. This parameter cannot be NULL. The value can be zero or G3XDDC_DEVICE_STATE_ERROR_HIGH_TEMP if critical temperature is detected and the device is turned off. In this case the application should call CohSetPower to turn off explicitly.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Structures

G35DDC_DEVICE_INFO

Contains information about G35DDC device.

C/C++ declaration


#pragma pack(push,1)



typedef struct

{

    CHAR        DevicePath[MAX_PATH];

    BYTE        InterfaceType;

    CHAR        SerialNumber[9];

    WORD        HWVersion;

    WORD        FWVersion;

    BYTE        EEPROMVersion;    

    UINT32      Flags;

    UINT32      ChannelCount;

    UINT32      DDCTypeCount;   

} G35DDC_DEVICE_INFO;



#pragma pack(pop

Members

DevicePath
Device system path in a null-terminated string. It is used to open the device using object interface.
InterfaceType

Device interface type. The value can be one of the following:

G3XDDC_INTERFACE_TYPE_PCIE
The device is connected to the computer via PCI express.

G3XDDC_INTERFACE_TYPE_USB
The device is connected to the computer via USB.

SerialNumber
Serial number in null-terminated string.
HWVersion
Version of the hardware.
FWVersion
Version of the firmware.
EEPROMVersion
EEPROM structure version.
Flags
Hardware configuration flags. It can be combination of the following values:

ValueMeaning
G35DDC_FLAGS_EXTERNAL_REFERENCEThe device supports external reference.
G35DDC_FLAGS_AUDIO_OUTPUTThe device has audio output connector.
G35DDC_FLAGS_COHERENTThe device supports coherent mode.

ChannelCount
Number of channels. It is always 3. In coherent mode each device has single processing channel.
DDCTypeCount
Number of DDC types supported by the DDC1.

COH_G35DDC_DEVICE_SET

Contains information about G35DDC device set.

C/C++ declaration


#pragma pack(push,1)



typedef struct

{

    UINT32              DeviceCount;

    G35DDC_DEVICE_INFO  *DeviceInfo;   

} COH_G35DDC_DEVICE_SET;



#pragma pack(pop

Members

DeviceCount
Number of devices in the device set / number of items in the array pointed to by the DeviceInfo member.
DeviceInfo
Pointer to array of device info structures of all the devices in the device set.

COH_G35DDC_DEVICE_SET_LIST

Contains information about G35DDC device set.

C/C++ declaration


#pragma pack(push,1)



typedef struct

{

    UINT32                  DeviceSetCount;

    COH_G35DDC_DEVICE_SET   *DeviceSet;  

} COH_G35DDC_DEVICE_SET_LIST;



#pragma pack(pop

Members

DeviceSetCount
Number of devices sets / number of items in the array pointed to by the DeviceSet member.
DeviceSet
Pointer to array of device set structures.

G3XDDC_DDC_INFO

Contains information about DDC type.

C/C++ declaration


#pragma pack(push,1)



typedef struct

{

    UINT32  SampleRate;

    UINT32  Bandwidth;

    UINT32  BitsPerSample;

} G3XDDC_DDC_INFO;



#pragma pack(pop

Members

SampleRate
Sample rate of I/Q signal in Hz.
Bandwidth
Useful bandwidth in Hz.
BitsPerSample
Number of bits per sample. It can be 16 or 32. It is used to determine bits per sample for DDC1.

G3XDDC_AMS_CAPTURE_RANGE

Contains information about DDC type.

C/C++ declaration


#pragma pack(push,1)



typedef struct

{

    UINT32  Tune;

    UINT32  Lock;

} G3XDDC_AMS_CAPTURE_RANGE;



#pragma pack(pop

Members

Tune
Initial capture range in Hz.
Lock
Capture range (in Hz) used when AMS demodulator is locked.

COH_G35DDC_CALLBACKS

Contains pointers to user-defined functions to be registered as callback functions.

Each callback function is called in context of thread created by the API. If some shared data are accessed inside callback functions, it is recommended to use a mutual-exclusion synchronization method. The application should not call any G35DDC API function from inside callback functions, otherwise it can cause deadlock or the application can become to unpredictable state.

C/C++ declaration


#pragma pack(push,1)



typedef struct

{

    COH_G35DDC_DDC1_STREAM_CALLBACK                 DDC1StreamCallback;

    COH_G35DDC_IF_CALLBACK                          IFCallback;

    COH_G35DDC_DDC2_STREAM_CALLBACK                 DDC2StreamCallback;

    COH_G35DDC_DDC2_PREPROCESSED_STREAM_CALLBACK    DDC2PreprocessedStreamCallback;

    COH_G35DDC_AUDIO_STREAM_CALLBACK                AudioStreamCallback;

} COH_G35DDC_CALLBACKS;



#pragma pack(pop)

Members

DDC1StreamCallback

Pointer to a user-defined function to be registered as DDC1 stream callback. It is called by the API to pass coherent I/Q samples from DDC1 of all the devices in the device set to the application at once. The DDC1 streaming is started using the CohStartDDC1 function.

C/C++ declaration

VOID __stdcall DDC1StreamCallback(UINT32 DeviceCount,CONST VOID **Buffers,UINT32 NumberOfSamples,UINT32 BitsPerSample,DWORD_PTR UserData);

Parameters

DeviceCount
Specifies number of I/Q sample buffers in the array pointed to by the Buffers. It is equal to number of devices in the device set (see the CohGetDeviceCount function).
Buffers
Pointer to the array of pointers to the buffers which contain I/Q sample sets from DDC1. Sample rate and bits per sample is given by used DDC type, see the CohSetDDC1 function. One I/Q sample set consists of two samples. Order of the buffers in the array corresponds to hardware interconnect of G35DDC devices.
NumberOfSamples
Specifies number of I/Q sample sets in each buffer in the Buffers array. This value is equal to value of the SamplesPerBuffer parameter of the CohStartDDC1 function.
BitsPerSample
Specifies number of bits per sample. It is given by DDC type used for DDC1 and it can be 16 or 32. If it is 16, sample is 16bit integer (32bits per I/Q sample set), signed, little endian, from range -32768 to 32767. If it is 32, sample is 32bit integer (64bits per I/Q sample set), signed, little endian, from range -2147483648 to 2147483647.
UserData
User-defined data. It is value passed to the CohSetCallbacks function as the UserData parameter.
IFCallback

Pointer to a user-defined function to be registered as IF callback. It is called by the API to pass IF snapshots from specified device of the device set to the application. Sending of IF snapshots is started using the CohStartIF function.

C/C++ declaration

VOID __stdcall IFCallback(UINT32 DeviceIndex,CONST SHORT *Buffer,UINT32 NumberOfSamples,WORD MaxADCAmplitude,UINT32 ADCSamplingRate,DWORD_PTR UserData);

Parameters

DeviceIndex
Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Buffer
Pointer to the buffer which contains samples directly received from ADC. Sample rate is 100 MHz, sample is 16bit signed little endian.
NumberOfSamples
Specifies number of samples in the buffer pointed to be the Buffer parameter. This is usually 65536.
MaxADCAmplitude
Specifies maximum amplitude. Measurement of the maximum is started at the end of the previous snapshot to the current one. The possible value is 0 to 32767.
ADCSamplingRate
Specifies sample rate of the ADC in Hz. It can vary a little bit because of temperature instability.
UserData
User-defined data. It is value passed to the CohSetCallbacks function as the UserData parameter.
DDC2StreamCallback

Pointer to a user-defined function to be registered as DDC2 stream callback. It is called by the API to pass I/Q samples from DDC2 to the application. The DDC2 streaming can be started using the CohStartDDC2 function.

C/C++ declaration

VOID __stdcall DDC2StreamCallback(UINT32 DeviceIndex,CONST FLOAT *Buffer,UINT32 NumberOfSamples,DWORD_PTR UserData);

Parameters

DeviceIndex
Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Buffer
Pointer to the buffer which contains I/Q sample sets from DDC2. Sample rate is given by the DDC type of the DDC2. Use the CohGetDDC2 function to determine current DDC type of the DDC2. Sample is 32bit IEEE float from range -1.0 to 1.0. One I/Q sample set consists of two samples.
NumberOfSamples
Specifies number of I/Q sample sets in the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the CohStartDDC2 function.
UserData
User-defined data. It is value passed to the CohSetCallbacks function as the UserData parameter.
DDC2PreprocessedStreamCallback

Pointer to a user-defined function to be registered as preprocessed DDC2 stream callback. It is called by the API to pass preprocessed I/Q samples from DDC2 of device to the application. The samples are filtered by the demodulator filter, notch filter and affected by AGC or fixed gain. The DDC2 streaming can be started using the CohStartDDC2 function.

C/C++ declaration

VOID __stdcall DDC2PreprocessedStreamCallback(UINT32 DeviceIndex,CONST FLOAT *Buffer,UINT32 NumberOfSamples,

            FLOAT SlevelPeak,FLOAT SlevelRMS,DWORD_PTR UserData);

Parameters

DeviceIndex
Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Buffer
Pointer to the buffer which contains preprocessed I/Q sample sets from DDC2. Sample rate is given by the DDC type of the DDC2. Use the CohGetDDC2 function to determine current DDC type of the DDC2. Sample is 32bit IEEE float from range -1.0 to 1.0. One I/Q sample set consists of two samples.
NumberOfSamples
Specifies number of I/Q sample sets in the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the CohStartDDC2 function.
SlevelPeak
Specifies peak signal level in Volts evaluated from samples stored in the buffer pointed to by the Buffer parameter.
SlevelRMS
Specifies RMS signal level in Volts evaluated from samples stored in the buffer pointed to by the Buffer parameter. For detailed information how to convert RMS signal level to dBm, see remarks of the CohGetSignalLevel function.
UserData
User-defined data. It is value passed to the CohSetCallbacks function as the UserData parameter.
AudioStreamCallback

Pointer to a user-defined function to be registered as audio stream callback. It is called by the API to pass audio samples from the device of the device set to the application. The audio streaming is started using the CohStartAudio function. The callback is invoked three times for each audio buffer (see description of the Type parameter).

C/C++ declaration

VOID __stdcall AudioStreamCallback(UINT32 DeviceIndex,UINT32 Type,CONST FLOAT *Buffer,UINT32 NumberOfSamples,DWORD_PTR UserData);

Parameters

DeviceIndex
Specifies index of device in the device set. It can vary from zero to one less than number of devices in the device set.
Type
Specifies type (stage) of audio samples stored in the buffer pointed to by the Buffer parameter. Value of this parameter can be one of the following:

ValueMeaning
0The buffer contains audio samples affected by audio gain (see CohSetAudioGain).
1The buffer contains audio samples affected by audio gain and audio filter (see CohSetAudioGain and CohSetAudioFilter).
2The buffer contains audio samples affected by audio gain, audio filter and volume (see CohSetAudioGain, CohSetAudioFilter, CohSetVolume and CohSetMute).
Buffer
Pointer to the buffer which contains samples of audio signal. The signal is mono, sample rate is 48000 Hz, sample is 32bit IEEE float from range -1.0 to 1.0.
NumberOfSamples
Specifies number of samples stored in the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the CohStartAudio function.
UserData
User-defined data. It is value passed to the CohSetCallbacks function as the UserData parameter.

G3XDDC_DRM_STATUS

Contains information about DRM demodulator/decoder status.

C/C++ declaration


#pragma pack(push,1)



typedef struct

{

    BOOL            Valid;



    struct

    {

        BOOL        SyncFound;

        BOOL        FACDecoded;

        BOOL        SDCDecoded;

        BOOL        AudioDecoded;

        SHORT       NumberOfAudioFrames;

        SHORT       NumberOfAudioErrors;

    } DecodingState;



    INT32           Mode;

    double          RFBandwidth;

    BYTE            Interleaver;

    SHORT           SDCQam;

    SHORT           MSCQam;

    BYTE            MSCQamType;

    double          CoderateH;

    double          CoderateA;

    double          CoderateB;

    double          EstimatedSNR;

    WCHAR           TextMessage[128 + 1 + 16];

   

    struct

    {

        BYTE        Content;

        WCHAR       DynamicLabel[256];

        WCHAR       Country[256];

        WCHAR       Language[256];

        WCHAR       ProgramType[256];

        double      AudioBitrate;

        double      TextMsgBitrate;

        double      MultimediaBitrate;

        double      DataBitrate;

    } ServiceInfo[4];



    struct

    {

        BOOL        Valid;

        BYTE        AudioCoding;

        BOOL        SBR;

        INT32       AudioMode;

    } AudioDecoderInfo[4];

} G3XDDC_DRM_STATUS;



#pragma pack(pop)

Members

Valid
The value is non-zero if content of the structure is valid. It is zero, if content of the structure is not valid.
DecodingState

Structure that contains status of the decoder modules.

Members

SyncFound
Status of the sync detection. It is non-zero if sync detected.
FACDecoded
Status of the FAC decoder. It is non-zero if FAC decoded.
SDCDecoded
Status of the SDC decoder. It is non-zero if SDC decoded.
AudioDecoded
Status of the audio decoder. It is non-zero if audio decoded.
NumberOfAudioFrames
Number of audio frames in the transmission frame. It is -1 if this information is not available.
NumberOfAudioErrors
Number of audio frames that were invalid.
Mode
Used DRM robustness mode. It can be one of the following:

ValueMeaning
G3XDDC_DRM_STATE_MODE_NOT_DETERMINED_YETRobustness mode is not determined yet.
G3XDDC_DRM_STATE_MODE_ABroadcast is using DRM robustness mode A.
G3XDDC_DRM_STATE_MODE_BDRM robustness mode B.
G3XDDC_DRM_STATE_MODE_CDRM robustness mode C.
G3XDDC_DRM_STATE_MODE_DDRM robustness mode D.

RFBandwidth
Occupied RF bandwidth in kHz. It is zero if it is invalid or this information is not available (yet).
Interleaver
Interleaver length. It can be one of the following:

ValueMeaning
G3XDDC_DRM_STATE_INTERLEAVER_LONGLong interleaver used (2 sec).
G3XDDC_DRM_STATE_INTERLEAVER_SHORTShort interleaver used (400 msec).

SDCQam
Coding of the SDC (QAM). It is zero if this information is not available (yet).
MSCQam
Coding of the MSC (QAM). It is zero if this information is not available (yet).
MSCQamType
Used QAM coding for the MSC. It can be one of the following:

ValueMeaning
G3XDDC_DRM_STATE_QAM_TYPE_STDStandard
G3XDDC_DRM_STATE_QAM_TYPE_HIER_SYMHierarchical symmetrical
G3XDDC_DRM_STATE_QAM_TYPE_HIER_MIXHierarchical mixed

CoderateH
Used code-rate for hierarchical coding, values less than or equal to zero indicate not available or not used.
CoderateA
Used code-rate for protection level A, values less than or equal to zero indicate indicate not available or not used.
CoderateB
Used code-rate for protection level B, values less than or equal to zero indicate indicate not available or not used.
EstimatedSNR
Estimated SNR in dB of the decoded signal.
TextMessage
Decoded text message for the selected service in 16bit Unicode null-terminated string.
ServiceInfo

Array of four structures which contain general information on the services.

Members

Content
Type of the service. It can be combination of the following:

ValueMeaning
G3XDDC_DRM_STATE_SERVICE_CONTENT_EMPTYGiven service is not used, it contains no data, all other members of the structure are invalid.
G3XDDC_DRM_STATE_SERVICE_CONTENT_AUDIOGiven service contains audio data.
G3XDDC_DRM_STATE_SERVICE_CONTENT_TEXTMSGGiven service contains text messages.
G3XDDC_DRM_STATE_SERVICE_CONTENT_MULTIMEDIAGiven service contains multimedia data.
G3XDDC_DRM_STATE_SERVICE_CONTENT_DATAGiven service contains application specific data.

DynamicLabel
16bit Unicode null-terminated string containing dynamic label of the service.
Country
16bit Unicode null-terminated string containing the signaled country for this service.
Language
16bit Unicode null-terminated string containing the signaled language for this service.
ProgramType
16bit Unicode null-terminated string containing the signaled program type for this service.
AudioBitrate
Data rate for the audio content. It is zero if this information is not available.
TextMsgBitrate
Data rate for the text message content. It is zero if this information is not available.
MultimediaBitrate
Data rate for the multimedia content. It is zero if this information is not available.
DataBitrate
Data rate for the data content. It is zero if this information is not available.
AudioDecoderInfo

Array of four structures which contain audio decoder specific information on the services.

Members

Valid
If it is non-zero, audio decoder information are valid, if it is zero, audio decoder information are invalid and all other members of the structure contain no valid data.
AudioCoding
Used audio coding. It can be one of the following:

ValueMeaning
G3XDDC_DRM_STATE_AUDIO_CODING_AACAudio coding for given service is AAC.
G3XDDC_DRM_STATE_AUDIO_CODING_CELPAudio coding for given service is CELP.
G3XDDC_DRM_STATE_AUDIO_CODING_HVXCAudio coding for given service is HVXC.
G3XDDC_DRM_STATE_AUDIO_CODING_RFUReserved for future use.

SBR
If it is non-zero, SBR is used, if it is zero, SBR is not used.
AudioMode
The value depends on audio coding. It can be one of the following:

ValueMeaning
G3XDDC_DRM_STATE_AUDIO_MODE_AAC_MONOMono
G3XDDC_DRM_STATE_AUDIO_MODE_AAC_PARAM_STEREOParametric stereo
G3XDDC_DRM_STATE_AUDIO_MODE_AAC_STEREOStereo
G3XDDC_DRM_STATE_AUDIO_MODE_AAC_RFUReserved for future use
G3XDDC_DRM_STATE_AUDIO_MODE_CELP_NO_CRCAudio data is without CRC
G3XDDC_DRM_STATE_AUDIO_MODE_CELP_CRCCRC used
G3XDDC_DRM_STATE_AUDIO_MODE_CELP_RFU_10Reserved for future use
G3XDDC_DRM_STATE_AUDIO_MODE_CELP_RFU_11Reserved for future use
G3XDDC_DRM_STATE_AUDIO_MODE_HVXC_RFU_00Reserved for future use
G3XDDC_DRM_STATE_AUDIO_MODE_HVXC_RFU_01Reserved for future use
G3XDDC_DRM_STATE_AUDIO_MODE_HVXC_RFU_10Reserved for future use
G3XDDC_DRM_STATE_AUDIO_MODE_HVXC_RFU_11Reserved for future use