Smart Logic Control Programming - Danfoss VLT FC 102 Series Design Manual

Application Examples Design Guide

7.1.6 Smart Logic Control Programming

The Smart Logic Control (SLC) is essentially a sequence of
user-defined actions (see 13-52 SL Controller Action)
executed by the SLC when the associated user-defined
event (see 13-51 SL Controller Event) is evaluated as TRUE
by the SLC.
Events and actions are each numbered and are linked in
pairs called states. This means that when event [1] is
fulfilled (attains the value TRUE), action [1] is executed.
After this, the conditions of event [2] is evaluated, and if
evaluated TRUE, action [2] is executed and so on. Events
and actions are placed in array parameters.
Only one event will be evaluated at any time. If an event is
evaluated as FALSE, nothing happens (in the SLC) during
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the present scan interval and no other events are
evaluated. This means that when the SLC starts, it
evaluates event [1] (and only event [1]) each scan interval.
Only when event [1] is evaluated TRUE does the SLC
execute action [1] and start evaluating event [2].
It is possible to program from 0 to 20 events and actions.
When the last event/action has been executed, the
sequence starts over again from event [1]/action [1].
Figure 7.4 shows an example with three events/actions:
Figure 7.4 An Example with Three Events/Actions
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