NI PCI-4474 data acquisition ContAccelSamps-IntClk-AnlgStart.c

[giaulo]

I need to acquire the acceleration data with my NI PCI-4474 connected with an accelerometer.
The PCI-4474 is correctly configured under OpenSuse 11.3. This is the nilsdev output:

NI PCI-4474: "Dev1"

I modified the ContAccelSamps-IntClk-AnlgStart.c in the Nidaqmx documentation examples:

/*********************************************************************
*
* ANSI C Example program:
*    ContAccelSamps-IntClk-AnlgStart.c
*
*
*********************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <NIDAQmx.h>

#define DAQmxErrChk(functionCall) if( DAQmxFailed(error=(functionCall)) ) goto Error; else

int32 CVICALLBACK EveryNCallback(TaskHandle taskHandle, int32 everyNsamplesEventType, uInt32 nSamples, void *callbackData);
int32 CVICALLBACK DoneCallback(TaskHandle taskHandle, int32 status, void *callbackData);

int main(void)
{
	int32       error=0;
	TaskHandle  taskHandle=0;
	char        errBuff[2048]={'\0'};

	/*********************************************/
	// DAQmx Configure Code
	/*********************************************/
	DAQmxErrChk (DAQmxCreateTask("",&taskHandle));
	DAQmxErrChk (DAQmxCreateAIAccelChan(taskHandle,"Dev1/ai0","",DAQmx_Val_PseudoDiff,-100.0,100.0,DAQmx_Val_AccelUnit_g,50,DAQmx_Val_mVoltsPerG,DAQmx_Val_Internal,0.004,NULL));
	DAQmxErrChk (DAQmxCfgSampClkTiming(taskHandle,"OnBoardClock",10000.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,1000));
	DAQmxErrChk (DAQmxCfgAnlgEdgeStartTrig(taskHandle,"Dev1/ai0",DAQmx_Val_Rising,30.0));
	DAQmxErrChk (DAQmxSetAnlgEdgeStartTrigHyst(taskHandle, 10.0));

	DAQmxErrChk (DAQmxRegisterEveryNSamplesEvent(taskHandle,DAQmx_Val_Acquired_Into_Buffer,1000,0,EveryNCallback,NULL));
	DAQmxErrChk (DAQmxRegisterDoneEvent(taskHandle,0,DoneCallback,NULL));

	/*********************************************/
	// DAQmx Start Code
	/*********************************************/
	DAQmxErrChk (DAQmxStartTask(taskHandle));

	printf("Acquiring samples continuously. Press Enter to interrupt\n");
	getchar();

Error:
	if( DAQmxFailed(error) )
		DAQmxGetExtendedErrorInfo(errBuff,2048);
	if( taskHandle!=0 ) {
		/*********************************************/
		// DAQmx Stop Code
		/*********************************************/
		DAQmxStopTask(taskHandle);
		DAQmxClearTask(taskHandle);
	}
	if( DAQmxFailed(error) )
		printf("DAQmx Error: %s\n",errBuff);
	printf("End of program, press Enter key to quit\n");
	getchar();
	return 0;
}

int32 CVICALLBACK EveryNCallback(TaskHandle taskHandle, int32 everyNsamplesEventType, uInt32 nSamples, void *callbackData)
{
	int32       error=0;
	char        errBuff[2048]={'\0'};
	static int  totalRead=0;
	int32       read=0;
	float64     data[1000];
	/* Change this variable to 1 if you are using a DSA device and want to check for Overloads. */
	int32       overloadDetectionEnabled=0;
	bool32      overloaded=0;
	char        overloadedChannels[1000];

	/*********************************************/
	// DAQmx Read Code
	/*********************************************/
	DAQmxErrChk (DAQmxReadAnalogF64(taskHandle,1000,10.0,DAQmx_Val_GroupByScanNumber,data,1000,&read,NULL));
	if ( overloadDetectionEnabled )
		DAQmxErrChk (DAQmxGetReadOverloadedChansExist(taskHandle,&overloaded));

	if( read>0 ){
		printf("Acquired %d samples. Total %d\r",read,totalRead+=read);
		for(int i=0; i< read; i++){
			printf("%f\n", data[i]);
		}
	}
	if( overloaded ) {
		DAQmxErrChk (DAQmxGetReadOverloadedChans(taskHandle,overloadedChannels,1000));
		printf("Overloaded channels: %s\n",overloadedChannels);
	}
	fflush(stdout);

Error:
	if( DAQmxFailed(error) ) {
		DAQmxGetExtendedErrorInfo(errBuff,2048);
		/*********************************************/
		// DAQmx Stop Code
		/*********************************************/
		DAQmxStopTask(taskHandle);
		DAQmxClearTask(taskHandle);
		printf("DAQmx Error: %s\n",errBuff);
	}
	return 0;
}

int32 CVICALLBACK DoneCallback(TaskHandle taskHandle, int32 status, void *callbackData)
{
	int32   error=0;
	char    errBuff[2048]={'\0'};

	// Check to see if an error stopped the task.
	DAQmxErrChk (status);

Error:
	if( DAQmxFailed(error) ) {
		DAQmxGetExtendedErrorInfo(errBuff,2048);
		DAQmxClearTask(taskHandle);
		printf("DAQmx Error: %s\n",errBuff);
	}
	return 0;
}

Unfortunately the program never calls the EveryNCallback callback...

Acquiring samples continuously. Press Enter to interrupt

Why the board can't acquire and print any data?

[giaulo]

I solved the problem commenting the following code: 

// DAQmxErrChk (DAQmxSetAnlgEdgeStartTrigHyst(taskHandle, 10.0));