Error -200077 When Trying To Read Differential Signal

Updated Jun 19, 2019

Reported In


  • NI-9205


  • NI-DAQmx

Issue Details

My C-Series module can read differential or single-ended signals. When I set the input terminal configuration input to Differential in my DAQmx Create Virtual Channel VI, I receive the following error message:

Error -200077 occurred at DAQmx Create Virtual Channel

Possible Reason(s): 
Measurements: Requested value is not a supported value for this property.


When using two channels as a differential signal, the correct physical channel must be assigned to DAQmx Create Virtual Channel VI. The appropriate channel and signal pairs can be found in the Getting Started document for your specific module.

Using the NI-9205 as an example, the Getting Started document shows that AI0 and AI8 are differential pairs and is assigned to Channel 0.

To read from this differential signal, you will need to set the physical channel in your DAQmx VI to Channel ai0 (eg. Channel Name: Mod3/ai0). Setting it to channel ai8 would result in the error above.