Siemens SIMATIC S5 Manual page 91

IP 266
Backlash
Backlash
M : Motor
Figure 5-9. Backlash Outside the Control Loop (compensatible)
Conditions for correct operation:
• Positive mechanical coupling between drive and slide
- when a distance > backlash value is traversed.
• Reference point has been approached
- when the distance to zero mark recognition is > backlash value.
• Following a drive movement within the permissible play of the backlash
(follow-up mode), the conditions for correct operation are no longer fulfilled.
A positive mechanical coupling must be reestablished between the drive and
the slide.
• Overswing can also result in loss of positive mechanical coupling. This is
possible when the overswing movement caused the distance traversed to be
less than the backlash. Overswing can be avoided by reducing the Kv factor.
EWA 4NEB 812 6057-02
Machine Data, Modes and Traversing Programs
M T
Reversal of direction
T
M
M T
Axis movement around the backlash
T: Tachogenerator : Incremental encoder
Displayed actual value increases
Actual value display remains constant
although the encoder is generating
pulses axis passes through the back-
lash
After traversing the path = backlash
value, the actual value display shows the
actual value to be on the decrease
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