Slc Application Example - Danfoss VLT HVAC Design Manual

Application Examples
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.
Max. ref.
P 3-03
Preset ref.(0)
P 3-10(0)
State 1
Preset ref.(1)
P 3-10(1)
Term 18
P 5-10(start)
Set the ramping times in 3-41 Ramp 1 Ramp Up Time and 3-42 Ramp 1 Ramp Down Time to the wanted times
t acc × n norm ( par . 1 − 25 )
t ramp =
ref RPM
Set term 27 to No Operation (5-12 Terminal 27 Digital Input)
Set Preset reference 0 to first preset speed (3-10 Preset
Reference [0]) in percentage of Max reference speed
(3-03 Maximum Reference). Ex.: 60%
Set preset reference 1 to second preset speed (3-10 Preset
Reference [1] Ex.: 0 % (zero).
Set the timer 0 for constant running speed in 13-20 SL
Controller Timer [0]. Ex.: 2 sec.
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State 2 State 3
2 sec
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Start
event P13-01
State 1
Event 1/
Action 1
Stop
event P13-02
State 4
Event 4/
Action 4
Set Event 1 in 13-51 SL Controller Event [1] to True [1]
Set Event 2 in 13-51 SL Controller Event [2] to On Reference
[4]
Set Event 3 in 13-51 SL Controller Event [3] to Time Out 0
[30]
Set Event 4 in 13-51 SL Controller Event [4] to False [0]
Set Action 1 in 13-52 SL Controller Action [1] to Select preset
0 [10]
Set Action 2 in 13-52 SL Controller Action [2] to Start Timer
0 [29]
Set Action 3 in 13-52 SL Controller Action [3] to Select preset
1 [11]
State 2
Event 2/
Action 2
Stop
event P13-02
State 3
Event 3/
Action 3
Stop
event P13-02
2 sec
119
6 6