DAQmxAddGlobalChansToTask to allow scanning channel twice

[jharris66]

Hi,

I was wondering if this would be the correct syntax to allow sampling a channel twice in a scan list:

for (row = 1; row < numrows; row++)
{
   strRow = getstring(row);
   DAQmxCreateAIVoltageChan(task, phychan, strRow, .......);
}

DAQmxAddGlobalChansToTask(task, "1");   // adding row=1 channel to end of scan list

Note that we only need to add one virtual 'row'  to task.

Thank you.

[chris88]

Hi jharris66

If you want to sample a channel twice I think it's better to configure a continuous aquisiton task and run it just twice.

for (i=1;i<2;i++) {

DAQmxErrChk (DAQmxReadAnalogF64(taskHandle,nSamples,10.0,DAQmx_Val_GroupByScanNumber,gData,nSamples*gNumChannels,&numRead,NULL));
Error:

if( DAQmxFailed(error) ) {
DAQmxGetExtendedErrorInfo(errBuff,2048);

}

This will run twice the analog read intead of re configure the whole task.