A0025218
31 Optimization of settings T
n
and K
p
A Actual value
B Time
1 T
n
too small
2 T
n
too large
3 K
p
too large
4 K
p
too small
5 Optimum setting
Actuating signal outputs via contacts (R237 to R2310)
Each control contact outputs a cyclical signal whose intensity corresponds to the
controller's actuating value. A distinction is made according to the type of signal cycle:
• Pulse length modulation
The bigger the calculated manipulated variable is, the longer the contact affected
remains picked up. The period T can be set to be between 0.5 and 99 s (field R238).
Outputs with pulse length modulation are used to activate solenoid valves.
• Pulse frequency modulation
The bigger the calculated manipulated variable is, the higher the switching frequency of
the contact affected. The maximum switching frequency 1/T can be set to be between 60
and 180 min
-1
(field R239). The on-time t
on
is constant. It depends on the set maximum
frequency and is approx. 0.5 s for 60 min
-1
and approx. 170 ms for 180 min
-1
. 170 ms.
Outputs with pulse frequency modulation are used to activate directly controlled
solenoid dosing pumps.
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