Overview Of Position Controller - Siemens SIMATIC S7-300 Manual

9.7 Position controller
Overview
The closed-loop position controller performs the following tasks:
The position controller is configured as a proportional-action controller. In its
environment are a number of function units that provide support by perform-
ing special tasks within the complex of movement control, and that can be
adapted to axis conditions by means of a variety of machine data.
The diagram 9-6 gives you an overview of the function units and the machine
data acting upon them.
MD40 MD41 MD42
Interpolator Jolt
v
filter
t
MD19
MD21 MD22
(setpoint)
MD19 – Direction adjustment
MD21 – Software limit switch - start
MD22 – Software limit switch - stop
MD23 – Maximum speed
MD24 – Target range; position reached,
stop (PEH)
MD25 – Monitoring time
MD26 – Idle range
MD30 – Backlash compensation
MD31 – Directional reference, backlash
Fig. 9-6

Overview of position controller

FM 354 Servo Drive Positioning Module
guidance of the drive at the proper speed during execution of a movement
precise approach of the axis to the programmed target position
maintenance of the axis in position in the face of interfering factors.
MD30, MD31 MD38 MD44
Position
Position
compari-
controller
son
+
Drift
compen-
–
sation
X3
Following-error
monitoring
from encoder
MD39
(actual value) MD26
MD37 –
MD38 –
MD39 –
MD40 –
MD41 –
MD42 –
MD43 –
MD44 –
MD45 –
Description of Functions
MD45
+
–
MD19
MD37
Fehler
MD25
MD24
Control signal Servo Bit 16
Positioning loop amplification
Min. following error, dynamic
Acceleration
Deceleration
Jolt time
Set voltage, max.
Offset compensation
Voltage ramp
MD23 MD43
D/A converter
10 V
X2
to drive
(actuating value)
9-69