User Manual

Control concept
Superposed plant controls
5
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Objects 3 and 2 are switched at the same time as object 5. Object 1 remains
switched on.
Alarm management
Block CMD_CTL is alarmable and differentiates process from system alarms.
A process alarm occurs, when:
● One of the monitored aggregates is not switched on.
● One of the referenced aggregates cannot be switched on.
The exception value [EcptVal] becomes the present plant operating mode as a
reaction to a process alarm. In addition, an alarm is sent.
A system alarm occurs for the following configuration efforts:
● A referenced aggregate is not available.
● A referenced aggregate is not a commandable object.
● Impermissible priorities are used (priorities 2, 5, 14, 16 are allowed).
● [ValPgm] or [EcptVal] are outside the permissible range.
● The referenced aggregates have a different number of operating modes.
The command control attempts for a system alarm to enable all referenced
blocks for local control. The four commandable priorities are commanded – in
other words enabled to Not commanded: Life safety (2), plant safety (4),
specific command control (14) and system control (16).
The response of the block to an alarm can be defined. The following
mechanisms have been incorporated to prevent hunting in the plant.
● Basic and standard: When the block goes into alarm, the exception value
[EcptVal] is switched. When all the aggregates are ready for switching
again, CMD_CTL automatically tries to implement the present plant
operating mode [PrVal]. If all the aggregates are ready for direct switching
immediately after implementation of the exception value [EcptVal], hunting
is likely to occur. In this case, CMD_CTL prevents any further switch-on
attempt, and the required plant operating mode [PrVal] must be changed.
● Extended: When the block goes into alarm, the exception value [EcptVal] is
switched. The alarm has to be reset by the user, and there is therefore no
risk of hunting.
02:00
01:00
00:30
1 2 3 4 5 6 7 8
4
1
Object nr.
State monitoring
Switch-on mode
Switch-off delay
Switch-off mode
Operating states
Priority
None None None
None
Delayed
Delayed
Delayed
Delayed
On On
Spec. cmd
Spec. cmd
Spec. cmd
Spec. cmd
Spec. cmd
Spec. cmd
Spec. cmd
Spec. cmd
Switch-off 7Switch-off 8 Switch-off 6
Switch-off 2Switch-off 3
Sequence 1Sequence 2Sequence 3
Objects 8, 7 and 6 are switched off in parallel.
The transition to sequence 2 occurs as
soon as the 30 sec. delay has expired.
Object 4 remains on, object 5 is
switched off at priority level 5. The transition
to sequence 1 occurs immediately
without delay.
Objects 3 and 2 are switched off in parallel.
Object 1 remains on.
Sequence 1
Sequence 2
Sequence 3
00:30 01:00 02:00
Switch-off 5
Delayed 0:30
Delayed 1:00
Delayed 2:00