Position Controller - Siemens SINUMERIK 840D sl Commissioning Manual

10.5.7

Position controller

Control loops
The closed-loop control of a machine axis consists of the cascaded closed-loop control
circuits of current controller, speed controller and position controller.
Figure 10-12 Control loops
Traversing direction
If the axis does not traverse into the desired direction, the appropriate adaptation is made in
the following machine data:
● MD32100 AX_MOTION_DIR (traversing direction)
The value "-1" reverses the direction of motion.
Control direction
If the control direction of the position measuring system is incorrect, it can be adjusted with
the following machine data:
● MD32110 ENC_FEEDBACK_POL (sign of actual value)
Servo gain
To obtain high contour accuracy, a high loop gain (K
required. However, an excessively high K
impermissibly high machine loads.
The maximum permissible K
the feedforward control or DSC, of the drive and the mechanical system of the machine.
Note
The first commissioning is performed without feedforward control.
A K
IBN CNC: NCK, PLC, drive
Commissioning Manual, 07/2007, 6FC5397-2AP10-3BA0
factor of "0" leads to the position controller being cut.
V
factor causes overshoot, instability and
V
factor is dependent on the dynamic response and the use of
V
10.5 Parameterize axis data
factor) of the position controller is
V
NCK start-up
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