3 Product Description
C-863.12 Mercury Controller
MS249E
Version: 1.2.1
29
value at an arbitrary point using the
POS
command (p. 181). The axis is not moved
here. The controller knows the absolute axis position afterwards.
INFORMATION
During startup using PIMikroMove, referencing is done via a reference move by default.
Knowledge of the commands and parameters described here is not needed for referencing
using PIMikroMove.
INFORMATION
To achieve maximum repeatability when referencing, each reference move comprises the
following steps:
1.
First move to the switch selected. The maximum velocity is specified via parameter 0x49
(
Closed-Loop Velocity (Phys. Unit/s)
, equivalent to setting with the VEL command).
2.
Stop on reaching the switch edge. The higher the velocity on approach, the farther the axis
overruns the edge of the switch (overshooting).
3.
Move in the opposite direction to compensate for overshoot.
4.
Second move to the switch selected. The maximum velocity is specified via parameter 0x50
(
Velocity For Reference Moves (Phys. Unit/s)
, specific velocity for reference moves only).
5.
Stop when reaching the switch edge.
6.
Move in the opposite direction to compensate for overshoot.
7.
Set the current position to a defined value, referencing is finished.
The lower the velocity is when approaching the switch, the less the overshoot will be and the
higher the repeatability. Therefore, the maximum value of parameter 0x50 should be as large
as the value of parameter 0x49, though ideally substantially less.
The actual velocities during the reference move are calculated from the values of the following
parameters and can be lower than the maximum values.
▪
Parameter 0x49 or 0x50
▪
Parameter 0x63 (
Distance Between Limit And Hard Stop (Phys. Unit)
)
▪
Parameter 0xC (
Closed-Loop Deceleration (Phys. Unit/s
2
)
)