Siemens SINUMERIK 840C Installation Instructions Manual page 226

09.95
220*
Backlash compensation 1st measuring system
Default value
0
In the case of axes with indirect measuring systems, mechanical backlash results in corruption
of the traversing path. When the direction is reversed, traverse is either shortened or extended
by the amount of backlash, depending on the design.
Positive backlash (normal case)
Backlash
M
Actual encoder value ahead of real actual
value (table): Too little table travel
The compensation value (amount of backlash) entered must be positive for positive backlash
and negative for negative backlash.
The control compensates the backlash specified in NC MD 220* (in all operating modes and in
all interpolation modes) each time the relevant axis changes its direction of travel.
Note:
As from SW 4, for 8 parameter sets
From SW 4 onwards interface signal "Reference point reached" is reset if MD 220* is
changed.
224*
228*
232*
236*
Default value
±99 999 999
Default value
For 224*, 232* + 99 999 999
For 228*, 236* – 99 999 999
A software limit switch may be used in addition to the customary range limit switch (hardware
limit switch). The operator enters the absolute position of the positive range limit for each axis.
©
Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
6 NC Machine Data (NC MD), NC Setting Data (NC SD)
Lower input limit Upper input limit
–16 000
Negative backlash
Table
Encoder
Real actual value (table) ahead of actual
encoder value: Too much table travel
1st software limit switch plus
2nd software limit switch minus
3rd software limit switch plus
4th software limit switch minus
Lower input limit Upper input limit
±0 99 999 999
6FC5197- AA50
6.4 Axis-specific MD 1 (axial data 1)
Units
16 000 units (MS)
Backlash
Units
units (MS)
Active on
NC Stop
Table
Rack
Encoder
Active on
NC Stop
Active on
NC Stop
Active on
NC Stop
Active on
NC Stop
6–41