User Manual

Control concept
Programming in D-MAP
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Plant
A plant consists of partial plants, aggregates, and components, which, as a rule, form a supply chain with
the chain links producer (here: boiler), distributor (pre-control, heating circuit), and consumer (radiator).
Operator interventions
Commands are executed at each link of the chain through operating interventions via HMI commands. The
impact on the plant (or the process) takes place via the corresponding function unit and automation
station.
Functional units
Functional units represent the software map of chain links and plant elements. The functional units contain
all control, monitoring, and limiting functions that are necessary for operation.
Information signals
Energy demand information can be passed on implicitly via the medium within the supply chain, e.g., if the
hot water supply temperature falls because of a rise in heat consumption, more heat energy must be
produced.
Information can also be represented by an explicit signal and transferred via a signal path (e.g., via a bus).
The following explicit signals have been defined in the Desigo system:
Explicit signals Signal flow Application
Demand signal Consumer to producer A plant functional unit communicates its demand (that is, operating mode, set
points) to another partial plant functional unit in the direction of the producer.
The demand signal eventually arrives at the producer.
Operating signal Producer to consumer A plant informs the downstream plants about its currently effective operating
state. This signal is only used as an exception and is therefore switched
depending on the situation.
Override signal Producer to consumer The producer demands a certain operating mode from a consumer. Forced
signals are more the exception than the rule and are therefore not
implemented in sample plants. Forced signals are used for solar plants and
wood furnaces among others, where the minimum heat production cannot be
controlled.
In addition to the functional units, there are two further elements that belong to the supply chain on the
software side:
● Coordinator: The coordinator combines the demand signals of downstream (to supply flow direction)
plants and delivers a resultant demand signal to the upstream plants. The coordinator also signalizes
the operating state of the upstream plants to the downstream plants.
● Dispatcher: The dispatcher determines the demand signals for the producers on the basis of the
resultant consumer demand signals. It decides which and how many producers must be activated.