Restoring axis position at controller start (P-AXIS-00761)

P-AXIS-00761

Restoring axis position at controller start

Description

When the controller is terminated, the axis position in the position controller is saved remanently. This parameter is used at controller start to automatically restore the last position saved for an axis. This assumes that the drive encoder supplies an absolute position within at least one motor revolution and that the axis was referenced when it was switched off.

By restoring the last axis position, homing can be dispensed with after a controller restart. This can also be helpful for axes with a large motion range if their absolute encoder overflows once or several times.

If the axis has an absolute encoder, the ON_ABSOLUT mode can be used. If the encoder only provides an absolute position within one motor revolution (no remanent revolution counter), the ON_RANGE mode should be used. The number of relevant encoder bits per motor revolution must also be specified in parameter P-AXIS-00355 for this mode.

Between switching off and switching on the controller, the axis may not move by more than half the absolute range. If necessary, this must be ensured by using a suitable motor brake Otherwise, the restored position is shifted by one or more absolute intervals.

Parameter

lr_param.restore_axis_position

Data type

STRING

Data range

OFF - At controller start, the last axis position is not restored

ON_RANGE - Restore the axis position within a restricted absolute range of the drive encoder

ON_ ABSOLUTE - Restore the axis position for axis with absolute encoder

Axis types

T, R, S

Dimension

T: ----

R, S: ----

Default value

OFF

Drive types

Simulation, SERCOS, Terminal, Lightbus, CANopen, Profidrive*

Remarks

This function is available as of CNC Build V3.1.3080

*Profidrive available as of V3.1.3081.4.

The parameter P-AXIS-00315 (antr.profibus.read_abs_pos_from_drive) must be set with Profidrive drives.