Modbus serial communication in sbRIO9637

[Gaurav_NTNU]

Hei all,

I am a relative newbie in this field coming from a pure architecture/design background. I am working on setting up a DAQ system for my thesis work and looking Modbus communication using sbRIO 9636's RS485 port as a potential option.

I was able to make a Modbus chain work without including sbRIO board by connecting it directly to a computer and making VI using VISA serial communication but I want this to work with the board so it can run independently without a computer. I came to know that because RS 485 port in this sbRIO board goes via FPGA so normal VISA serial communication can't be used. I have tried all ways and looked everywhere on Forums and can't find a suitable way to run it. I worked with the attached VIs but they are meant for cRIO 9871.

Can someone share or describe how I can make suitable VIs for Modbus communication where port goes via FPGA especially for sbRIO boards?

Thanks a lot in advance

Gaurav Chaudhary

[NIRebecca]

Hey Gaurav_NTNU,

If you new to Modbus this is a good place to start: Modbus Protocol Reference Guide

We can look at MODBUS From the tcp/ip port MODBUS from the serial port. There's also examples of getting those libraries working on sbRIOs in the forums

Serial: https://forums.ni.com/t5/Multifunction-DAQ/single-board-rio-using-modbus/td-p/2330274

 "I have applied the modbus library on sbrio9636 successfully."

Let us know how it goes, 

Rebecca