Can I Use One Physical Ethernet Port for Shared Variable & Modbus Communication?

Updated Oct 25, 2018

Reported In


  • Ethernet Cable
  • Ethernet Device

Operating System

  • NI Linux Real-Time
  • Windows

Issue Details

I only have available one physical Ethernet port in my device, but I want to use network published shared variables (using NI-PSP) and Modbus communication. Is it possible to use both with a single physical Ethernet Port?


Yes, it is possible to use both as long as you have two virtual ports. Virtual ports are used in TCP and UDP to identify unique end-to-end connections. They are called "virtual ports" because a single physical connector can serve multiple connections.

For more Information about Modbus and NI-PSP refer to related links section.

Additional Information

By default NI-PSP uses port 59110, and the most common port used by Modbus is 502. You are able to change this default Ports but the consideration you must be aware of is not to use the same port for different tasks.


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