Commissioning; Adapting The Controller Direction Of Effect To The Controlled System - Siemens SIPART DR22 Manual

Manual
4

Commissioning

4.1

Adapting the controller direction of effect to the controlled system

D Definitions
Normal effect system
Increasing y causes increasing x; e.g. increasing energy supply or increasing mass flow
causes increasing temperature.
Normal effect final control element (valve):
Increasing current or actuating command +∆y cause actuator to open (increasing y); e.g. a
greater energy supply or greater mass flow. y
In cascade controls the folow--up controller for observing the direction of effect of the master
controller is considered part of the controlled system.
The direction of effect of the controller is referenced to the main controlled variables FE1
and FE3. The following statements apply for normal effect transmitters (increasing physical
variable causes increasing transmitter current), increasing process display (dE*>dA*) and
no reservation in the freely connectable range or no falling characteristic in linearization in
the fixed connected range.
D Direction of effect of system and actuator known
K controller
The following is prescribed:
Direc- Direc- Direc-
tion tion tion
of effect of effect of effect of effect of effect of effect
of the of the of the
system actua- system
tor and the
actua-
tor
normal normal
normal l
rever- rever-
sing sing
normal normal rever- rever-
rever- rever sing
sing i
rever- normal
sing i
Two more lines could be added to the table which are useless in practice: normal effect system in which the actual values
falls with a rising change in the manipulated variable.
Table 4-1 Controller direction of effect and y-display direction of effect of the system and actuator
direction of effect in K-controllers
SIPART DR22 6DR2210
C79000-G7476-C154-03
4.1 Adapting the controller direction of effect to the controlled system
An
Select the desired effect here:
pressing the right key
causes in manual operation
20 mA 20 mA
actua- valve
on
ting
current-
ly
100 % rises opens
0 % falls opens
0 % falls closes
100 % rises opens
100 % rises closes
0 % falls opens
is the displayed manipulated variable.
This gives settings of S54 or S56 This gives settings of S54 or S56
and S68 and function
of the controller
actual S54
value/ or (cP)
control- S56
led
variable
rises 0 pos.
rises 1 neg.
rises 1 neg.
falls 1 neg.
rises 0 pos.
falls 0 pos.
4 Commissioning
Kp S68 y =
An
0 y
1 100 % - y
1 100 % - y
0 y
0 y
1 100 % - y
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