Siemens Sinumerik 840DiE sl - Drift Compensation

01/2007
11.5 Axes and spindles
11-343
© Siemens AG 2007 All Rights Reserved
SINUMERIK 840Di sl Manual (HBIsl) – 01/2007 Edition
11.5.16 Drift compensation
Digital drives are not subject to drift or compensate for it automatically.
Because ADI4 does not support acyclic services on the PROFIBUS DP, drift
compensation must be performed manually by entering the appropriate com-
pensation value in the axial machine data
S MD36720 DRIFT_VALUE (basic drive value)
Manual drift compensation is performed with the axis at zero speed as follows:
Requirements
– Zero speed of the axis
– Axis enables pending
S Speed–controlled axis
The drift causes constant traversing of the axis. To compensate for the drift,
the compensation value is incremented/decremented step by step depend-
ing on the direction of the drift until the axis reaches zero speed.
S Position–controlled axis
The drift causes a constant following error or position setpoint  0. To com-
pensate for the drift, the compensation value is incremented/decremented
step by step depending on the direction of the drift until following error or
position setpoint = 0 is displayed.
HMI Advanced:
Operating area switchover > Diagnosis > Service displays > Service
axis/spindle
!
Warning
If an axis is used for the function DSC (Direct Servo Control)
S MD32640: STIFFNESS_CONTROL_ENABLE (dyn. stiffness control) = 1
no drift compensation may be enabled for that axis.
Drift compensation causes extreme speed fluctuations during switch–on/off of
the DSC function.
Table 11-35 Drift compensation: Machine data
Number Identifier Name/remarks Refer-
ence
Axis–specific ($MA_ ... )
36720 DRIFT_VALUE Basic drift value G2
Digital drives
ADI4
Manual
drift compensation
Machine data
11 NCK Commissionin
g
with HMI Advanced