KROHNE OPTISENS AAC 050 EN - Manual (Page 18)

Manual OPTISENS AAC 050
OPTISENS AAC 050 18
For any type of controller you have to enter one or two set points, and you have to tell the device whether
these set points are reached by increasing or decreasing the measured value.
You can choose between three different controller versions:
ON/OFF controller
The ON/OFF controller switches ON if the measured value exceeds the set point and OFF if it drops back
below it or vice versa. Dosage is always carried out with 100% (ON) or 0% (OFF). The parameter for an
ON/OFF controller is the hysteresis.
P controller
The P controller or proportional controller reduces the dosage in the vicinity of the set point proportional to
the control deviation. This is easily achieved if the analog output is used as steady control output. If the
relays are used, the proportional reduction is achieved by either reducing the switch frequency (Impulse-
frequency controller) or reducing the time within a given period of time in which the relay is ON (pulse-pause
controller). The parameters for a P controller are the P range and the impulse- frequency or the pulse+
pause time and the minimum pulse.
PI controller
The PI controller is a P controller with an additional I function. Adjustments and parameters are the same as
for a P controller. Additionally the integral action time has to be adjusted which determines the I function.
The I function eliminates the P controller’s disadvantage of a remaining steady-state deviation.
5.1 ON/OFF controller
Main menu
.
You can choose different
.
Set points and
controller version
Controller versions for
Set points Set Point S1 S1 and S2
.
1.50 mg/l
.
P range S1
.
0.00 mg/l
Integral time S1
000 sec.
Set Point S2
0.50 mg/l Controller settings
P range S2 .
0.00 mg/l .
Integral time S2 Direction S1
000 sec. raise
Direction S2
Basic settings lower
Basic settings . Hysteresis
Contr. settings 0.01 mg/l