Appendix E
62
HA0142T Rev 12 February 2011
E.3 Error Correction
E.3.1 Backlash correction
The term
backlash
refers to the tendency of the stage to reach a different position
depending on the direction of approach.
Backlash can be overcome by always making the last portion of a move in the same
direction, conventionally the positive direction. Consider the situation in Fig. E.5, a
positive
move, from 10 to 20 mm, is carried out as one simple move, whereas a
negative
move, from 20 to 10 mm, first causes the stage to overshoot the target
position and then move positively through a small amount.
Fig. E.5 Backlash correction
The particular stage selection will usually have this type of ‘backlash correction’
enabled as its default mode of operation, but it can be overridden if the overshoot part
of the move is unacceptable for a particular application.
See Chapter 6 Software Reference, Move/Jogs Tab for details on setting the
backlash correction.
negative move
positive move
10mm
20mm
position
