En
gl
is
h (
G
B)
34
15.2 Application examples of different
output signals and final control
elements
The purpose of the output module of the controller is
to convert the calculated manipulated variable into a
signal which can be processed by a corresponding
final control element. If you use a dosing pump with
a current input, it must be controlled differently from
e.g. a gas dosing unit with servomotor.
As the values of the different parameters depend on
the type of control element, you must consider
different parameters for each of these output signals.
15.2.1 Limit contact controller
Application
•
Upward control direction of chlorine
concentration using chlorine bleaching leach.
•
Control of dosing pump by power supply.
Description
•
The actual value of the required chlorine
concentration falls below the setpoint:
– Dosing pump for chlorine bleaching leach is
switched on.
•
The actual value of the required chlorine
concentration exceeds the setpoint:
– Dosing pump for chlorine bleaching leach is
switched off.
•
The hysteresis
– Widens the setpoint into a band.
– Prevents unsteady switching on and off of
dosing pump.
Fig. 51
Limit contact controller
Parameter settings
Note
Always adapt the parameter settings of
the following examples to the local
conditions!
T
M
03
71
07
16
1
3
t
SP 1
Off
On
{
Hysteresis
Chlorine concentration
Switching status of the pump.
time
SP 1
Required chlorine concentration, e.g. 55 %.
Pulse frequency for SP 1
0
SP 2
-
*)
Pulse frequency for SP 2
-
X
p
0
T
n
0
T
v
0
Hysteresis
e.g. 1 %
Interpulse period
-
Actuating time
0
Minimum pulse width
0
Required code functions
1, 6, 8, 10
Other code functions
As required
*)
"-": without function (no setting required)
