Behavior Following Specific Events In Redundant Operation - Siemens Simatic 6ES7 157-0AD81-0 A0 Series Manual

Operation of the DP/PA Link and the Y Link
8.3 Behavior following specific events in redundant
operation
The table below shows the behavior of the IM 157 following specific events in
redundant operation.
Table 8-2

Behavior following specific events in redundant operation

Master-reserve switchover with a changed
configuration
Failure of a CPU
Failure of the active channel
Failure of the passive channel
Failure of an IM 157
8-6
Event Reaction
The link is switched over in a bumpless
manner from the active channel to the
channel that has up to now been passive.
If this also causes the active channel of the
redundant DP master system to fail: see
Failure of the active channel.
Otherwise: see Failure of the passive
channel.
The link is switched over in a bumpless
manner from the active channel to the
channel that has up to now been passive.
The failed channel is indicated on the
corresponding IM 157 by the "BF 1" LED.
No consequences for the link.
The failed channel is indicated on the
corresponding IM 157 by the "BF 1" LED.
A diagnostic message is generated in the
system.
If the active IM 157 fails, the link is switched
over in a bumpless manner to the channel
that has up to now been passive.
DP/PA Link and Y Link Bus Couplings
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