Redundancy via SCA-RS
SICAM RTUs, SICAM AK Redundancy
Unrestricted
19
DC2-026-2.07, Edition 10.2016
1.1.3
Voting
1.1.3.1 Automatic Voting
The voting process is based on the definition of priorities in the redundancy table (see also the
description of the priority levels in sections
•
CPU Redundancy
The voting between both BSEs is performed automatically by the M-CPU (automatic
voting with CPU redundancy).
•
AU Redundancy
The voting between both AUs is performed automatically by the SCA-RS, regardless of
the type of switchover (global and line-by-line redundancy switchover)
1.1.3.2 Application-Related Voting
The voting process is usually performed by an external application based on user data
messages received (more precisely: redundancy status information control messages) (see
also section
). However, the voting is primarily application-related,
the voter thereby also makes use of the error messages of the sum and detail diagnostic, in
order to generate its own redundancy control messages for the switchover.
This way the behavior of the external application can be defined with any level of flexibility.
The voting process is therefore not based on the definition of priorities.
1.1.4
Redundancy Switchover
For AU redundancy there are 2 switchover possibilities:
•
Global redundancy switchover
(automatic voting by SCA-RS; application-related voting)
The entire AU is either in the redundancy state
active
or
passive
.
•
Line-by-line redundancy switchover
(automatic voting by SCA-RS; application-related voting)
Only defined elements of an AU are switched to the passive state. Within an AU, some
elements can be active, others passive.
