User Manual

Control concept
Superposed plant controls
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The block is not alarmable for Desigo 7.
Out of service
The block can be taken out of commissioning using [OoServ]. The following
occurs when switching [OoServ] to On:
● Immediately abort of switch on and off sequences and monitoring.
● All objects are commanded with a release of the priorities: Life safety (2),
plant safety (4), specific command control (14) and system control (16)
Superposed power control PWR_CTL
The power control function block PWR_CTL is used for control and monitoring
of the performance of a number of energy producers (multiple boiler systems,
refrigeration machines, etc.). As is the case for command control CMD_CTL,
the data is exchanged bilaterally between power control and the individual
energy producers (boiler, refrigeration aggregate, among others), via
referencing. Since the energy producers are generally implemented in the form
of logical aggregates, and contain local logic, the PWR_CTR block
communicates only with MVAL blocks.
The control strategy is based on the use of tables and is designed for multi-
stage energy producers. Additional energy-producer stages are connected or
disconnected in accordance with the actual power demand. For modulating
energy producers, a stepped output is converted into a proportional output
within the aggregate. This makes it possible to handle the full power range
(0…100%) in one stage, or to divide the power range into several stages (e.g.,
Stage 1: 0…20%; Stage 2: 20…40%; etc.).