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Why Do the NI 9870 and NI 9871 Serial Ports Not Show Up in the FPGA I/O Constant?

Updated Nov 30, 2023

Reported In


  • NI-9870
  • NI-9871


  • LabVIEW
  • LabVIEW FPGA Module

Issue Details

I have placed an I/O constant or control as the input to my FPGA I/O Method or Property Node and I want to select my 9870/9871 module or one of its ports.  Why does it not show up as one of the selectable inputs?


FPGA I/O elements are a part of the LabVIEW project.  The 9870/9871 modules do not have FPGA I/O elements in the project and therefore do not support direct interaction with the I/O pins due to the RS-232, RS-485 or RS-422 protocol being used.  Because of this, they cannot be selected in an I/O constant or control.  To configure the I/O Method or Property Node for the 9870/9871 ports, complete the following:
  1. Add an FPGA Method I/O Node (FPGA I/O Panel) to the block diagram.
  1. Right-click the node, and choose the module and port from the Select Item menu. 
  1. Select the method you need to use.

Additional Information

In LabVIEW 2012 and NI-RIO 12.0, there is a known issue where the terminals will not auto populate after a Method is selected. This issue has been fixed in LabVIEW 2012 SP1 and NI-RIO 12.1.