6 NC Machine Data (NC MD), NC Setting Data (NC SD) 04.96
6.7 Axis-specific MD 2 (axial data 2)
Filter time constant acceleration determination for quadrant
error compensation (as from SW 4)
1256*
Default value Lower input limit Upper input limit Units
60 0 16 000 1 ms
Active on
NC Stop
This value is usually not altered by the user. The value should only be increased if the
compensation in the smallest speed range is insufficient.
Feedfwd control factor for rigid tapping (as from SW 2)
1260*
Default value Lower input limit Upper input limit Units
0 0 1 000 0.1 %
Active on
NC Stop
A P feedforward control factor can be entered for the axes involved in the function ”Rigid
tapping”. This machine data has the same meaning as that of NC MD 312*. NC MD 1260* is
only used if NC MD 1320* is not 0.
Grid spacing / ENDAT measuring step (as from SW 5.4)
1264*
Default value Lower input limit Upper input limit Units
0 0 16 000 -
Active on
Power On
The SINUMERIK 840C supports ENDAT absolute encoders where the ratio of grating
pitch/ENDAT measuring step as an integer can be divided by 4. If you enter an incorrect value,
this leads to measuring errors. The input values 0 to 7 are internally processed as the value 4
(default value for rot. EQN 1325). The grid spacing and the ENDAT measuring step must be
taken from the data sheet of the ENDAT absolute encoder.
Setpoint filter time constant
1272*
Default value Lower input limit Upper input limit Units
0 0 1 000 0.1 ms
Active on
NC Stop
The setpoint filter prevents overshooting of positions in the case of a dynamic speed
feedforward control of 100 %.
Note:
As from SW 4, for 8 parameter blocks
Setpoint
filter
Setpoint
+
Setpoint
speed
Actual position value
KV
Feedforward factor
Symmetrizing
filter
d
dt
6–166 © Siemens AG 1992 All Rights Reserved 6FC5197- AA50
SINUMERIK 840C (IA)