Insert MTU into Running S800 I/O Cluster
Say I have a Profibus I/O cluster using redundant CI840A's directly attached via the electrical ModuleBus to 5 modules (using TU810 MTU) then connected with an extension cable to 5 more modules (using TU890 MTU) with a TB807 terminator on the 10th module. The documents say the MTU's
"...cannot be replaced or repaired with power applied. Disconnecting an MTU breaks the ModuleBus communications bus and removes power to the MTUs that follow. MTUs mounted in the middle (between the ModuleBus master, cluster modem and the number 12 MTU) need to have the preceding or following MTUs moved in order to disconnect the ModuleBus connector."
So if I disconnect the extension cable to slip an MTU into the 6th postion, will modules 1-5 continue to function normally during the process? The language is not clear, IMO, whether communications are broken or not for upstream modules 1-5.
I have the same question about removing the TB807 terminator to add on an 11th or 12th MTU: would that kill communications (forcing OSP channel values) to the entire cluster?
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