OMRON Modbus connection


Thread Starter

Daniel Rallo

Hello Readers,

I am working with a User of OMRON CQM1H/CQM1, which he wants to communicate with Schneider Modicon Telemecanique Systems.

I've thought in a Modbus RS485 card. Is ModBus Card/Port Available in OMRON CQM1H/CQM1 Series?,

OMRON commercial service said to me that is not available Modbus protocol running in an OMRON RS485 card. Is there any 3rd manufacturer that sells this kind of product?. I'm thinking in somebody who could provide some OMRON RS485 coupler, but with Modbus protocol embedded.

Other possibility would be some kind of gateway to converting OMRON protocol to Modbus. But I don't know anything about it.

What is the Protocol this OMRON Series uses?.


Daniel Rallo.
As mentioned in the other response, the MARC Omnicom will do that. All Omron PLCs have Host Link protocol built in. You should have no problems with that.

I've programmed both PLCs before, if you get stuck.


David Wooden

The CQM1H with the Serial Communication Board (CQM1H-SCB41) can support RS-485. The native protocol is called Host Link. The Serial Communication Board also supports Protocol Macros, which make it relatively easy to emulate third party protocols such as Modbus. Information
on the Serial Communication Board, Protocol Macro and Host Link protocol are all available in the
CQM1H Programming Manual, which can be downloaded at:


David Wooden
Senior Software Engineer, Systems Integration
Automation and Enterprise Solutions Group
TAS Division of Omron Electronics LLC
Office: (847) 884-7034 Extension 432
Fax: (847) 884-9383
E-mail: [email protected]