Setting the Transceiver Wire Mode of Ports on National Instruments Serial Boards

Updated Dec 3, 2019

Reported In


  • RS-485


  • LabVIEW
  • Measurement & Automation Explorer (MAX)



Operating System

  • Windows

Issue Details

How can I set the transceiver wire mode of ports on my National Instruments serial boards?


You can set the Wire Mode property through Measurement and Automation Explorer (MAX) or LabVIEW. For details on the different wire modes you can set, refer to Transceiver Modes on NI-485 Serial Cards.  


This option allows you to set the wire mode in MAX first before any application development.
  1. Search for NI MAX in the Start Menu and right click >> Run as Administrator
  2. Expand Devices and Interfaces and select the RS-485 serial port of interest.
  3. Select the Advanced tab at the bottom of the window. 
  4. Select the desired wire mode from the Transceiver Mode drop-down menu. 


The Wire Mode property can be set programmatically using LabVIEW property nodes. This option allows you to easily set a different wire mode. 

Refer to the shipping example RS-485 Transceiver located in LabVIEW Help >> Find Examples >> Hardware Input and Output >> Serial, or follow the steps below to incorporate the property node into your application. 
  1. Add a VISA property node on your block diagram. 
  2. Wire the VISA serial session of the port of interest to the reference input. Alternatively, you can right-click on the reference input, create a constant or control, and select the port of interest. 
  3. Select Property >> Serial Settings >> Wire Mode to configure the property.  
  4. Right-click and select Change All to Write to set the property node to write.
  5. Right-click on the Wire Mode input to create a constant or control. Refer to Serial Settings: Wire Mode to see the values it can take on.


    Additional Information

    The NI-VISA driver exposes the Wire Mode property in MAX and LabVIEW. If you are experiencing issues getting to the serial settings or do not see the correct serial port, refer to Serial COM Ports Missing in MAX or LabVIEW.