I've just started a new job where ABB Symphony DCS has been employed. I'm trying to learn more about the Cnet network that connects the PCUs together.
I'd like to use something like Phoenix Digital OCMs to create a fault-tolerant counter rotating fiber ring for this system, but I haven't yet been able to locate good technical data on the network/protocol.

Is Cnet really just plain old ethernet under a trademarked name? If so, this is an easy thing to implement.
Is it the same as any other Bailey network protocols?

Anyone with ABB Symphony/Harmony experience that has knowledge/advice for me, please share if you can.
Thanks!

 

Hi,

There are a number of technologies that Bailey/ABB uses within the Symphony DCS. The PCU-to-PCU communications is via a proprietary redundant ring structure. It is sort of like token-ring except: 1) every node can send a token, and 2) its multicast (msgs aren't from 1 PCU to another PCU, but 1 PCU to all PCUs).

The ring is PCU to PCU redundant. For example you can break ring 1 between PCUs 1 and 2 and break ring 2 between PCUs 2 and 3 and the system will operate no problem.

Because of the proprietary nature of the PCU-PCU communications it will be extremely difficult to get 3rd party devices.

I hope that this helps.

Regards
Pete

 

Thanks for the reply Pete.