using profibus or ethernet over Fiber optic


Thread Starter


Wanted to replace one section of the FO with either profi or some sort of arrangement which converts profibus to some easily available & compatible media with S7 plc.

Any suggestions?
We use Siemens Simatic NET OLMs (Optical Link Modules) in combination with the Siemens RS485 Repeaters for MCC controls.


James Ingraham

Well, that's not a lot to go on. There are lots of ways to get Profibus from copper to fiber and back. Siemens has Optical Link Modules (OLM) for just that purpose, and there are lots of other options as well; Hirschmann, Phoenix Contact, Weed, Harting, S.I. Tech / Bit-Driver, etc. Of course, it has to be the RIGHT fiber-optic; duplex 62.5/152nm. You need to know if it's single-mode or multi-mode. If it's not the right connector type you'll have to deal with that.

Incidentally, that all goes equally for Ethernet, but with even more options for how to do it and vendors that have solutions. All the above players are still in, plus all the industrial Ethernet folks like N-Tron, Moxa, etc. and all the non-industrial Ethernet guys like Cisco, 3Com, Allied Telesyn, HP...

More data on the application will narrow down information on the solution.

-James Ingraham
Sage Automation, Inc.
Thank you gray for the reply. I wanted to replace one section of fiber optic cable because of following reasons:

1. It's costly, needs special tools & skills to terminate & time consuming if replaced.

Is it possible to convert it to Profibus & than connect it to remote I/O?