Siemens SIMOTICS S-1FL6, Руководство по эксплуатации

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Control functions
7.5 Internal position control (IPos)
SINAMICS V90, SIMOTICS S-1FL6
Operating Instructions, 04/2019, A5E36037884-007
253
7.5.11 Position tracking
The position tracking function can be used to realize the following features:
● Setting up a virtual multi-turn for a single-turn absolute encoder
● Extending the position area
● Enabling the load position to be reproduced when using gearboxes
If the position tracking function is enabled, the actual position value can be saved in a power-
off retentive memory when you power off the drive. When you power on the drive again, the
saved position value can be read by the drive.
Virtual multi-turn encoder
For a single-turn absolute encoder with position tracking activated (p29243 = 1), p29244 can
be used to enter a virtual multi-turn resolution. This enables you to generate a virtual multi-
turn encoder value from a single-turn encoder. The actual position value in r2521 is limited to
2
32
places.
● When position tracking is deactivated (p29243 = 0):
Encoder actual position value range = actual single-turn resolution
● When position tracking is activated (p29243 = 1):
Encoder actual position value range = actual single-turn resolution × virtual multi-turn
resolution (p29244)
Tolerance window
The tolerance window is preset to a quarter of one encoder revolution. After switching on the
drive, the difference between the saved position and the actual position is determined.
Based on the difference, the following situations apply:
● Difference being within the tolerance window:
The position is reproduced based on the actual encoder value.
● Difference exceeding the tolerance window:
The fault F7449 (for EPOS control mode) is output.
NOTICE
Multi-turn position loss resulting from the axis movement when the drive is power-off
When the drive is power-off, if the axis moves, the drive does not store the multi-turn
position (when using the virtual multi-turn encoder). The actual position loses.
• Make sure that the motor holding brake function is enabled when you use the position
tracking function.