Omron RS-485 Protocol


Thread Starter


Hi all.
I am looking for information on Omron's RS-485 protocol for their remote I/O modules. ANY information would be appreciated.
Thanks in advance.

Cristian Gliga


The RS-485 is an electrical standard for data transmission. To be more precise, it uses a differential line and is half duplex. For more details you can search the web. There are a lot of articles about RS-485 interface. Over the RS-485 line one can use either 8-bit protocol or 9-bit protocol. Let me know what protocol you are interested in and I will reply with details.

Cristian Gliga - Systems Integrator
Hi Christian.

I am attempting to interface to an Omron PLC's RS-485 link. I am unsure of whether it uses 8 or 9 bit protocol. I do have a lot of general information on the RS-485 interface, but need to know format of the Ormon's bit stream. I am specifically interested in the bit stream used for Omron's remote I/O modules and retrieving discreet bit information and sending discreet bit information.

Thanks in advance.

i m also looking for rs-485 protocol for my project
well u can find a lot on rs-485 from and type rs-485 in search, u will get lots of sites and PDF's to download.

if u have any knowledge about its protocol then please contact me.