Positioning Unit; Position Controller - Aventics R412004397 Instrucciones De Servicio

AVENTICS | Position Controller | R412004397–BDL–001–AC
4.2

Positioning unit

The positioning unit consists of:
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Pneumatic cylinder
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Position sensor (integrated in the cylinder)
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Valves (mounted on the cylinder)
The analog position sensor determines the exact position of the
piston in the cylinder and thus the position of the piston rod. The
valves control the piston movement.
An operating voltage of 10 V is present at the position sensor
(potentiometer). The position sensor sends a signal (actual
value) between 0 and 10 V that is proportional to the piston
position in the cylinder (see Fig. 1 on page 50):
Piston position in the cylinder
Bottom
Center
Covers
4.3

Position controller

The position controller is a controller with proportional
characteristics. It has analog inputs and outputs. The task of the
position controller is to move the cylinder to the position that
corresponds with the set point. For this purpose, the position
controller compares the set point to the actual value.
The following relationship exists between the set point and
actual value:
Set point - actual value = deviation
The deviation is the margin for the control variables that control
the valves in the positioning unit.
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Negative deviation: The valves are controlled in such a manner
that the cylinder retracts. The actual value decreases.
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Positive deviation: The valves are controlled in such a
manner that the cylinder extends. The actual value
increases.
Design and applications
Actual value
Approx. 0 V
Approx. 5 V
Approx. 10 V
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