Serial (COM) Port on Real-Time Controller Doesn't Show Up in NI MAX

Updated Jul 26, 2023

Reported In


  • PXI Controller


  • NI-Serial

Issue Details

I need to access the serial port on my Real-Time PXI controller. When I go to the controller in the Remote Systems list in NI MAX and then open the Devices and Interfaces list, the serial (COM) port does not show up.


If your controller has a built-in serial port that is not showing up when you view the Remote System in NI MAX, you likely do not have the NI-Serial drivers installed on the controller.
  1. Find the controller in the Remote Systems list in NI MAX.
  2. Click the arrow next to the controller name to expand its sub-list.
  3. Right-click on Software and select Add/Remove Software.
  4. In the list of software to install, make sure to include NI-Serial RT.
  1. Continue through the wizard to finish the installation. Your serial port should now show up under Devices and Interfaces.

Additional Information

After the port is recognized in NI MAX, you can use the port using the NI VISA driver.

Some other NI Real-Time controllers, such as CompactRIO, CompactDAQ, or Industrial Controllers, do not need NI-Serial RT to be installed on the controller for the serial port to show up or be used.