CEX Bus terminator (TB850) failed on a running system
Dear Sirs, we have a critical system with a stand-alone AC800M controller (Compact Control Suite).
In this system there was a failure of a TB850 CEX Bus Terminator that was hard to identify.
The customer is asking the following questions regarding this module, and I can't find the answer to them in the documentation.
- Is this module active or passive?
- Which is the MTBF of this kind of module?
- Can the controller run without this termination module?
- How probable is that this kind of fault happens again?
I would appreciate any information that could help me answer to the customer.
Thank you and best regards,
Voted best answer
I think the right way is to send your questions above to your official ABB contact.
AKS is a forum for exchanging of experience and Q&A, but most probably not the official place for so fundamental questions.
Anyhow, if you look carefully in the manuals, it is stated the following for the single CPU:
"If no units are used on the CEX-Bus, no bus termination is required"
So it depends on your configuration.
I suppose only, that TB850 is a passive unit
Most probably the CPU will work without TB850 (even when it is required - I tried it at my risk temporary) but better is to install all the terminators as required and described in the manuals. Nobody will provide parts, which are not necessary to install :-)
For me never happen fault in TB850 terminator.