int32 Tweezers::Degauss(float U, float duration)
{
clock_t startTime;
float freq = 100;
int bufferSize = (int)(5000 * duration);
float64 *data = new float64[bufferSize];
// fill buffer with data
for(int i=0;i<bufferSize;i++)
{
float64 amp = U * (1 - (double)i/(double)(bufferSize-1));
data[i] = amp * cos( 2.0 * PI * freq * (double)i/5000.0); // degauss Srate must be independent of run!!
}
DAQmxErrRtn(DAQmxClearTask(AOtaskHandle));
// create and setup analog task
DAQmxErrRtn(DAQmxCreateTask("AO",&AOtaskHandle));
DAQmxErrRtn(DAQmxCreateAOVoltageChan(AOtaskHandle,"Dev1/ao0","",-10.0,10.0,DAQmx_Val_Volts,NULL));
// configure sample clock for buffered write
DAQmxErrRtn(DAQmxCfgSampClkTiming(AOtaskHandle,"",5000,DAQmx_Val_Rising,DAQmx_Val_FiniteSamps,(int)(duration*5000)));
// write data and start task
DAQmxErrRtn(DAQmxWriteAnalogF64(AOtaskHandle,bufferSize,0,10.0,DAQmx_Val_GroupByChannel,data,&written,NULL));
startTime = clock();
DAQmxErrRtn(DAQmxStartTask(AOtaskHandle));
while(!done) {
DAQmxErrRtn(DAQmxIsTaskDone(AOtaskHandle,&done));
if (!done) Sleep(100);
}
done = false;
DAQmxErrRtn(DAQmxStopTask(AOtaskHandle));
residual = 0.0;
delete data;
}
int _tmain(int argc, _TCHAR* argv[])
{
TaskHandle task;
int acqTime = 6;
float64 sampleRate = 500000.0;
float64 linePeriod = .002;
int lineSamples = (int)(linePeriod * sampleRate);
int numLines = (int) (acqTime / (lineSamples/sampleRate));
int acqSamples = numLines * lineSamples;
int32 sampsWritten;
bool32 taskDone;
//Create the task
DAQmxCreateTask("a task", &task);
//Add AO channels
DAQmxCreateAOVoltageChan(task, "Dev1/ao0", "", -10, 10, DAQmx_Val_Volts, NULL);
//Configure timing
DAQmxCfgSampClkTiming(task, NULL, sampleRate, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps, acqSamples);
//Write output data
float64 *outputData = (float64*) calloc(acqSamples, sizeof(float64));
for (int i=0;i<numLines;i++)
{
for (int j=0;j<lineSamples;j++)
{
outputData[i*lineSamples + j] = ((float64) j/(float64)lineSamples) * 10.0;
}
}
DAQmxWriteAnalogF64(task, acqSamples, false, 10.0, DAQmx_Val_GroupByChannel, outputData, &sampsWritten, NULL);
printf("Wrote %d samples of data!\n", sampsWritten);
printf("Sample #33: %g\n", outputData[32]);
printf("Sample #121: %g\n", outputData[120]);
printf("Sample #6032: %g\n", outputData[6031]);
//Start Task
DAQmxStartTask(task);
printf("Started task...\n");
while (true)
{
DAQmxIsTaskDone(task,&taskDone);
if (taskDone)
break;
else
Sleep(1000);
}
//Clear Task
DAQmxClearTask(task);
return 0;
}
