Siemens sinumerik 840D sl Function Manual page 576

Normalize setpoint
The following axial machine data is used to normalize and limit the output voltage:
MD32250 $MA_RATED_OUTVAL and
MD32260 $MA_RATED_VELO
The maximum motor speed is entered in MD32260 $MA_RATED_VELO in rev/min. The
percentage in MD32260 $MA_RATED_VELO specifies the voltage at maximum motor speed
with respect to +/- 10 V. A setting of 80% means +/- 8V on the DMP module at maximum
motor speed. The percentage value must be adjusted according to the analog drive amplifier
used.
Example:
Maximum motor speed 6000 rev/min: MD32260 $MA_RATED_VELO = 6000
8V at motor speed 6000 rev/min: MD32250 $MA_RATED_OUTVAL = 80
4V are present on the DMP module at a motor speed of 3000 rev/min.
Note
Changes to the following machine data are not activated by NewConfig, but only after a
reset.
MD32250 $MA_RATED_OUTVAL and
MD32260 $MA_RATED_VELO
This is applicable only in relation to the analog axis function.
Drift compensation
A drift that needs to be compensated by the position controller occurs in every analog drive.
The "Analog axis" functions provides two different options for compensating drift. One of
these options involves a constant drift value that is entered in machine data MD36720
$MA_DRIFT_VALUE. This value is added to the position controller setpoint in every position
controller cycle and output.
The second method involves automatic drift compensation. This is activated with the
machine data MD36700 $MA_DRIFT_ENABLE = 1. A maximum drift value for automatic
compensation is specified in machine data MD36710 $MA_DRIFT_LIMIT. The drift is
compensated as soon as the analog axis is operating under closed-loop control, no setpoints
are applied from the IPO and the axis is stationary. As soon as the axis moves again, the
last compensation value is frozen and added to the setpoint in every position control cycle. If
the compensation value is higher than the value in machine data MD36710
$MA_DRIFT_LIMIT, alarm 75110 "Axis X1 has reached drift limit" is set and the drift value is
limited.
Note
Changes to machine data MD36700 $MA_DRIFT_ENABLE, MD36710 $MA_DRIFT_LIMIT,
MD36720 $MA_DRIFT_VALUE do not take effect with NewConfig, but only on reset. This is
applicable only in relation to the analog axis function.
Special functions: Analog Axis (TE2)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0
Detailed description
2.4 Setpoint
11