Omron PLC to B&B serial/fiber converter

[robertjo24]

We have a station that has an Omron PLC. It was connected to the main PLC via a B&B 485 to fiber converter. The fiber converter went bad and was replaced, and now the link does not work on the new fiber converters.

The Omron tech stated the communications on the Omron PLC is proprietary, not true RS-485, and therefore will not work with the 485-fiber converters. He said it never should have worked on the old converters, and can’t imagine how it did.

Does this sound reasonable to you?

Any info on the proprietary Omron “485” communications?

 

[robertjo24]

The field devices talking back to the master are G72C-ID16 units.

 

[NWBeaver]

The SYSMAC BUS used by the G72C-ID16 units is specified as being RS-485, Half-duplex, 187.5 kbps

Matching the baud rate could be an issue, along with other things like polarity and termination.

Omron also makes a Link Adapter, AL007-P, which is used with wired remote I/O to convert RS-485 to fiber.

 

[robertjo24]

In case anyone was interested...

Omron really does not have a real solution for their version of RS-485 to fiber (62.5 micron MM) conversion. All it seems their older models support is the 200 micron plastic fiber.

I was direced by their tech support to S.I. Tech. They actually manufacture an RS-485 to fiber converter (MM 62.5 micron) specifically for the Omron. They have a point to point unit (2127) , and a multi-drop unit (2128).