Bürkert 8791, Руководство по эксплуатации

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17
Function
function of the position control 7.2.
The position measuring system records the current position ( POS ) of the pneumatic actuator. The position controller
compares this actual position value with the set-point value ( CMD ) which is a standard signal. If there is a control
difference (Xd1), the actuator is aerated and deaerated via the control system. In this way the position of the actuator
is changed until control difference is 0. Z1 represents a disturbance variable.
Valve opening
Control valve Control system
Solenoid valves
Position measuring
system
Position
controller Position set-
point value
CMD Xd1
B1
E1
P
K
Z1
POS
Position control circuit
+
-
Signal flow plan of position controller Fig. 3:
english
Type 8791