Checking Status of the Relays on My NI 948x Relay Module

Updated Jan 18, 2023

Reported In


  • NI-9147
  • NI-9149
  • NI-9148
  • NI-9144
  • NI-9145

Issue Details

I am using an NI 948x relay module with Compact DAQ. I know that I can use the DAQmx Write VI to open and close the relays but how can I check the status of the relays to see if they are open or closed?


You can use the DAQmx Read VI with a DAQmx Digital Output channel to read the status of a relay on the NI 948x module. A Boolean value of True corresponds to a closed relay, and a Boolean value of False corresponds to an open relay. The VI below shows an example of how this is done in LabVIEW: