Do the C Series Relay Modules Reset when the Chassis is Power Cycled?

Updated Jul 19, 2019

Reported In


  • CompactDAQ Chassis
  • CompactRIO Chassis
  • C Series Relay Output Module

Issue Details

I'm using a relay module and a cRIO/cDAQ chassis. I am using the relay to power other equipment and need to know if it will keep its state when the cRIO or cDAQ is powered off or reset.


Each Relay module has different specifications and can behave differently in a cDAQ chassis versus a cRIO chassis, so please check the documentation regarding the particular module. Information for some of the relay modules is listed below.

NI 9481Power-on output state = Channels off
NI 9482Power-on output state = Channels off
NI 9485Relay type= Normally open solid-state relay (SSR) 

Additional Information

The reason the relays can behave differently in the different types of chassis is because the FPGA on the cRIO chassis can be used to hold the position of relays.  The RPGA is programmed with a bit file and will retain the relay values specified in the bit file until the file is changed or removed.


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