Siemens SIMATIC FM 453 Manual page 269

Synchronization is a defined point on the traversing path of the axis. It is defined by the me-
Point
chanical position of a reference-point switch or in association with a cyclic
zero mark of an incremental encoder.
Synchronization
Creating the position reference between the internal FM position value and
mechanical position of the axis.
Measured Value Irrespective of the approach direction, the synchronization point can be lo-
Synchronization cated on the side of the lower or the higher actual position values in relation
With Incremental
to the reference point switch position. It is demarcated by the rising edge of a
Encoders
zero pulse or by the reference point switch. This selection is made by the
MD18 (together with the approach direction).
Example
With reference to the synchronization point, the reference point can be lo-
cated on the side of the lower or the higher position actual values. In the "ref-
erence point approach" operating mode the machine axis additionally tra-
verses this distance, during its last phase of motion, once the synchronization
point has been found. Consequently, the axis halts the motion, in each
instance, exactly on the reference point.
Example
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
Measurement Cyclical zero mark
grid
Variant 1
Variant 2
RV –
Meas. grid Cyclical zero mark
RV – Reference point offset
Description of Functions
Axis direction +
RPS
Synchronization point
Axis direction +
RV +
Axis direction +
Synchronization point
Reference point
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