Operation As A Positioner - Burkert 8630 Operating Instructions Manual

Operating as a positioner
The actual position (POS) of the pneumatic actuator is measured via the position sensing system. The
controller compares this actual value of the position with the setpoint (CMD) , which can be specified as
a standard signal. If a control difference (Xd1) exists, a pulse-width modulated voltage signal is sent to
the positioning system as the correcting variable. With single-acting actuators, if the difference is positi-
ve, the pressurizing valve is driven via output B1; if it is negative, the exhaust valve is driven via output
E1. In this way, the position of the actuator is altered until the control difference is zero. Z1 represents a
disturbance.
CMD
Position setpoint
Xd1
Positioner
Position control
loop
B1
P
K
E1
Positioning Continious valve
system Sole-
noid
POS
Wegmeßsystem
Position sensor
S D
YSTEM ESCRIPTION
Z1
Valve opening
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