Closed-Loop Position Control; General Features; Position Actual Value Conditioning; Features - Siemens SINAMICS S120 Function Manual

7.8

Closed-loop position control

7.8.1

General features

The position controller essentially comprises the following parts:
● Position actual value conditioning (including the lower-level measuring probe evaluation
● Position controller (including limits, adaptation and the pre-control calculation)
● Monitoring functions (including standstill, positioning, dynamic following error monitoring
● There is still no position actual value conditioning for distance-coded measuring systems.
● Position tracking of the load gear (motor encoder), using absolute encoders for rotary
7.8.2

Position actual value conditioning

7.8.2.1

Features

● Correction value (p2512, p2513)
● Setting value (p2514, p2515)
● Position offset (p2516)
● Position actual value (r2521)
● Velocity actual value (r2522)
● Motor revolutions (p2504)
● Load revolutions (p2505)
● Spindle pitch (p2506)
● Position tracking (p2720ff)
7.8.2.2

Description

The position actual value conditioning implements the conditioning of the position actual
value in a neutral position unit LU (LENGTH UNIT). To do this, the function block uses the
encoder evaluation/motor control with the available encoder interfaces Gn_XIST1,
Gn_XIST2, Gn_STW and Gn_ZSW. These just provide position information in encoder
pulses and fine resolution (increments).
The position actual value is conditioned independently of whether the position controller is
enabled immediately after the system has booted and as soon as valid values are received
via the encoder interface.
Parameter p2502 (encoder assignment) is used to define from which encoder (1, 2 or 3), the
position actual value is sensed.
Drive functions
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
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and cam signals)
axes (modulo) as for linear axes.
Function modules
7.8 Closed-loop position control
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