Control Mode - Wika Cs4R Betriebsanleitung

8. Descriptions of the operating ... / 9. Control mode
8.4 Heater burnout alarm
Alarm behaviour
LED display
(EVT)
: Alarm is ON
: Alarm is OFF
The control LED (EVT) is lit if the alarm is ON and goes out if the alarm is OFF.

9. Control mode

9.1 PID
Proportional band (P)
■
The P component alters the manipulated variable depending on the deviation of the actual
value from the set point. The proportional band represents a "band" around the set point.
If the actual value is within the proportional band, then the manipulated variable is defined
in relation to the deviation of the actual value to the set point (pulsed with relay and logic
level outputs, for current output signals it is in the range of 4 mA < MV < 20 mA). If the
actual value lies outside this band, then the maximum or minimum manipulated variable
is delivered (maximum or minimum power). Enlarging the proportional band produces a
more stable transient effect, though the control is slowed down. If the proportional band is
reduced, one gets a faster control and also small disturbances are quickly controlled. If the
proportional band, however, is set too small, this can lead to undamped oscillations of the
actual value (so-called flywheel effect).
By setting the proportional band to "0" one gets an
Once the control variable has assumed a stable value within the range of the set point and
a constant actual value has been maintained, one gets the most suitable value by gradually
narrowing the proportional band under constant observation of the control result.
WIKA operating instructions model CS4R
Heater burnout alarm
ON
OFF
Alarm value, heater burnout alarm
low Load current
ON
high
OFF
/ control mode.
ON OFF
EN
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