This is part of the program
"
// build up a rect waveform
memset(m_Data,0,m_nSampleNumber*sizeof(double));
for(int i=0;i<m_PulseDutyFactor;i++)
{
m_Data[i]=m_nMagnitude;
}
/// build up the task
DAQmxErrChk(DAQmxCreateTask("",&m_TaskHandle));
DAQmxErrChk(DAQmxCreateAOVoltageChan(m_TaskHandle,"Dev1/ao0","",-10.0,10.0,DAQmx_Val_Volts,NULL));
DAQmxErrChk(DAQmxCfgSampClkTiming(m_TaskHandle,"",m_nFreq*1000.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,m_nSampleNumber));
long written;
DAQmxErrChk(DAQmxWriteAnalogF64(m_TaskHandle,1000,0,10.0,DAQmx_Val_GroupByChannel,m_Data,&written,NULL));
// start the task
DAQmxErrChk(DAQmxStartTask(m_TaskHandle));
....
/// change the output waveform (change the pulse duty factor )
if( m_TaskHandle!=0 ) {
double mag=m_nMagnitude;
m_PulseDutyFactor=pdf;
long written;
memset(m_Data,0,m_nSampleNumber*sizeof(double));
for(int i=0;i<m_PulseDutyFactor;i++)
{
m_Data[i]=m_nMagnitude;
}
res=DAQmxStopTask(m_TaskHandle);
// restart the task
res=DAQmxWriteAnalogF64(m_TaskHandle,1000,0,10.0,DAQmx_Val_GroupByChannel,m_Data,&written,NULL);
res=DAQmxStartTask(m_TaskHandle);
}
"
When I call "DAQmxStopTask", the task stop, but the analog output is random, sometimes it is zero and sometimes it is full-voltage (m_nMagnitude).
The question is:
Could I make the output on some determined value eg. full-voltage (m_nMagnitude)?
Or there some better sollution for me to change the continuous output waveform without a break (DAQmxStopTask) ?
