DAQmxCreateAIVoltageChan and DAQmxSetChanAttribute

[jharris66]

Hello,

We are implementing a DAQmx task with PXI-6255 and see alot of noise on a NRSE channel.  All the other channels in the task are created as RSE channels.

For the NRSE channel we first create the channel as follows:

DAQmxCreateAIVoltageChan (taskHandle, phyChan, virtChan, DAQmx_Val_RSE, 0,10,
     DAQmx_Val_Volts, NULL);

Then later on we set the terminal config using DAQmxSetChanAttribute:

DAQmxSetChanAttribute (taskHandle, phyChan, DAQmx_AI_TermCfg, DAQmx_Val_NRSE);

Do we need to use virtChan name in the DAQmxSetChanAttribute to ensure we get NRSE configuration?  We don't see an error when using phyChan name.

THanks in advance.

[David-H]

Hi jharris66,

This sounds to me like a grounding issue. Is your signal source floating or grounded? Please reference the following resource for wiring best practices:

http://www.ni.com/white-paper/3344/en/#toc2