Do I Need a Pull-up or Pull-down Resistor for NI 9425?

Updated Apr 13, 2023

Reported In


  • NI-9425

Issue Details

I would like to know about using a pull up resistor with digital input module NI 9425. 

Is there any pull up or pull down resistance built in the module? If yes, how can I access it?

What value of resistance does NI recommend to use as pull up resistance for 24V supply?



The NI 9425 does not have any pull-up or pull-down/current-limiting resistors at the inputs. The only built-in protection is 30 kOhm input impedance, as per the NI 9425 Datasheet.

You should be able to apply a 24 V logic input, without the need for additional circuitry for a pull-up resistance. Also, please note that the NI 9425 has a sinking input, as shown in the "NI 9425 Circuitry" diagram from page 4 of the NI 9425 Datasheet. Please check the "Additional Information" section below for more details.

Additional Information

For more information on sinking and sourcing inputs or outputs, please check the article in the related links below: What is the Difference Between Sinking and Sourcing Digital I/O?
If you would like to know the pull-up or pull-down resistor values for other DAQ hardware, please visit the link below: Internal Pull-up Pull-down Resistor Values on Digital I/O Lines of DAQ Devices