NI-DAQmx Internal Channels for Self-Diagnostics and Self-Calibration

Updated Jan 28, 2023

Reported In

Hardware

  • Multifunction I/O Device

Driver

  • NI-DAQmx

Issue Details

I would like to test my M Series device in NI-DAQmx to verify that the analog outputs and analog inputs are working. Are there any special channels I should use for diagnostics?

Solution

The following table is a list of internal channels for M Series devices. The subset of channels present varies by device. These channels are typically for self-calibration, and you can sample them as you would a physical channel present on the I/O connector.
 
Internal Channel NameDescription
_aignd_vs_aigndA differential terminal with the positive and negative terminals both connected to the ground reference for analog input.
_ao0_vs_aogndA differential terminal with the positive terminal connected to physical channel ao0 and the negative terminal connected to the ground reference for analog output.
_ao1_vs_aogndA differential terminal with the positive terminal connected to physical channel ao1 and the negative terminal connected to the ground reference for analog output.
_ao2_vs_aognd(For M Series devices only.) A differential terminal with the positive terminal connected to physical channel ao2 and the negative terminal connected to the ground reference for analog output.
_ao3_vs_aognd(For M Series devices only.) A differential terminal with the positive terminal connected to physical channel ao3 and the negative terminal connected to the ground reference for analog output.
_calref_vs_aigndA differential terminal with the positive terminal connected to the internal calibration reference voltage and the negative terminal connected to the ground reference for analog input.
_aignd_vs_aisenseA differential terminal with the positive terminal connected to the ground reference for analog input and the negative terminal connected to physical channel AI SENSE.
_aignd_vs_aisense2A differential terminal with the positive terminal connected to the ground reference for analog input and the negative terminal connected to physical channel AI SENSE2.
_calSrcHi_vs_aigndA differential terminal with the positive terminal connected to the calibration PWM and the negative terminal connected to the ground reference for analog input.
_calref_vs_calSrcHiA differential terminal with the positive terminal connected to the internal calibration reference voltage and the negative terminal connected to the calibration PWM.
_calSrcHi_vs_calSrcHiA differential terminal with the positive and negative terminals connected to the calibration PWM.
_aignd_vs_calSrcHiA differential terminal with the positive terminal connected to the ground reference for analog input and the negative terminal connected to the calibration PWM.
_calSrcMid_vs_aigndA differential terminal with the positive terminal connected to the calibration PWM and the negative terminal connected to the ground reference for analog input. _calSrcMid is the divided down version of _calSrcHi.
 
These internal channels are routed using an internal switching matrix, so no wiring or cabling is required. Refer to Internal Channels for M Series and NI 6010 Devices in  in NI-DAQmx Help for more information on internal channels.