I am continuosly measure DC Voltage on the analog input channels on the card NI-PCI 6014 and for test reasons I am feeding it with 0 V DC. However, the first measurements samples is some 10 V DC and after aprox. 20 seconds it's down to 1.5 V DC and remains there. I stop the measurements, wait a while and start again I get the same results. So I am woundering what is wrong, is it my PCI-card or is something wrong with my code?
Here's what I do:
DAQmxErrChk (DAQmxCreateTask(
"", &taskHandle));
DAQmxErrChk (DAQmxCreateAIVoltageChan(taskHandle, sDev, "", DAQmx_Val_Cfg_Default, -10.0, 10.0, DAQmx_Val_Volts, NULL));
for (;;)
{
DAQmxErrChk (DAQmxReadAnalogF64(taskHandle, nSampleBuffer, 10.0, DAQmx_Val_GroupByChannel, samplebuffer,
nSampleBuffer, &read, NULL));
Sleep(1000);
}
