PXI-6255 NRSE, RSE configuration

[jharris66]

Hello,

We are using PXI-6255 and are using 60 channels.  Our development environment is CVI.

Questions:

1)  We would like to have one scan list with 59 channels set as RSE and one channel as NRSE.  Is it ok to perform configuration using these steps:

    DAQmxCreateAIVoltageChan // with all 60 channels in channel list, initially setup as RSE

    DAQmxSetChanAttribute (task, ch, DAQmx_AI_TermCfg, DAQmx_Val_NRSE)     // for the one channel that is NRSE

2)  Can accuracy issues occur by combining NRSE and RSE signals in a scan list?

Thank you,

[Thomas-B]

Hi jharris66,

From what I can see, it looks like you should be able to perform the task with 59 RSE channels and 1 NRSE channel. The method you discuss may work. Another option would be to perform two “ DAQmxCreateAIVoltageChan” commands. One command would create the 59 channels with RSE, and other would create the 1 NRSE channel. Have you tried either of these methods yet?

The measurement accuracy should not be affected by the two different measurement configurations. Are you currently seeing problems with this?