Redundancy of PROFIBUS master


Thread Starter

Rob Cats

I am trying to deal with redundancy of PROFIBUS masters, which is an important functionality in DCS. I saw different solutions. Some vendors are proposing intelligent "y-switches" capable of handling switchover from two different masters, thus connecting slaves with a single interface; some others are proposing intelligent PROFIBUS masters with an embedded capability of a mutual
agreement on the mastership, and both masters are connected to the field in multi-drop to the chain of slaves.

In both cases the slaves are not aware of the tricks above, so any standard slave can be managed.

Unfortunately, as far as I know, there is no general statement from the committees about which is the "standard" way to manage MASTER redundancy.

Does anybody know more?

We installed a redundant Profibus setup in which a primary master (a PC with a PCI Profibus master card) was on line while a backup master (an identical PC) was in a standby mode and its Profibus master card was not actually on
line. A routine in the PC which happened to be the master at the time sent a "heartbeat" (via an Ethernet link) to the back up indicating it was still on line. If the back up lost this sinal, it triggered the back up to come on line and become the Primary.

This system has been in operation and working well for approximately two years in a 24/7 situation.

I hope this helps,

RIck Hudson