6.1.6 Smart Logic Control Programming
The Smart Logic Control (SLC) is essentially a sequence of user defined actions (see par. 13-52
SL Controller Action
) executed by the SLC when the
associated user defined
event
(see par. 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]
will be evaluated and if evaluated TRUE,
action [2]
will be 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 the present scan interval and no
other
events
will be 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, the SLC executes
action [1]
and starts 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]
. The illustration shows an example with three
events / actions
:
6.1.7 SLC Application Example
One sequence 1:
Start – ramp up – run at reference speed 2 sec – ramp down and hold shaft until stop.
Set the ramping times in par. 3-41
Ramp 1 Ramp Up Time
and par. 3-42
Ramp 1 Ramp Down Time
to the wanted times
tramp
=
tacc
×
nnorm
(
par
. 1
−
25)
ref
RPM
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®
HVAC Drive Design Guide
6 Application Examples
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