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HA0302T Rev A Feb 2016
Chapter 5
Pitch
- the pitch of the motor lead screw (i.e. the distance (in mm or degrees) travelled
per revolution of the leadscrew). Not applicable to MLS and DDS series stages and
preset to ‘1’.
Units
- the ‘real world’ positioning units (mm or degrees).
Homing
When homing, a stage typically moves in the reverse direction, (i.e. towards the
reverse limit switch). The following settings allow support for stages with both Forward
and Reverse limits.
Direction
- the direction sense to move when homing, either
Forward
or
Reverse
.
Limit Switch
- The hardware limit switch associated with the home position, either
Forward HW or Reverse HW
.
Zero Offset
- the distance offset (in mm or degrees) from the limit switch to the Home
position.
Velocity
- the maximum velocity at which the motors move when Homing.
Note
The
Min Pos
and
Max Pos
parameters can be used to restrict the working
range of the stage to a particular area of interest.
Note
For DDS and MLS stage users
. The Homing, Limit Switch and Motor
parameters described on the next two pages are not applicable for the
DDS and MLS series stages because the stage does not use a limit switch
as a reference point for homing. Instead, it uses a special reference
marker pulse from the encoder. Homing on these stages involves a
search for this reference marker. Initially, the stage moves in the forward
direction and if the reference marker is found before the stage hits the
forward limit switch, then homing is completed. If not, the stage reverses
direction and continues to search for the reference marker. Due to the
different method used, only the Homing Velocity parameter can be
adjusted, although normally the default value is suitable for nearly all
applications. All other parameters are greyed out.
Note
Typically, the following two parameters are set the same, i.e. both
Forward or both Reverse.
Note
The minimum velocity and acceleration/deceleration parameters for a
home move are taken from the existing move velocity profile parameters
