Siemens SINUMERIK 840C - Manual (Page 665)

09.95
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Siemens AG 2001 All Rights Reserved 6FC5197– j AA50 9–44
SINUMERIK 840C (IA)
9.5.3 Conventional quadrant error compensation (as from SW 2)
Corresponding
S
MD 1332*
data 1236*
1240*
1244*
1248*
1252*
1256*
S
MD 1804*, bit 6
1804*, bit 7
1824*, bit 0
Parameterization The friction feedforward control is activated axis-specifically via MD 1804*, bit 6.
If MD 1804*, bit 7 is set, the adaptation characteristic also becomes active.
The following machine data area available for parameterization:
MD 1232* Compensation value in range 2 [0.1 mV] [0.01 %] 1)
MD 1236* Compensation time constant [0.1 ms]
MD 1240* Compensation value in range 4 [0.1 mV] [0.01 %] 1)
MD 1244* Upper limit range 1 (a
1
) [100 units MS/s 2 ]
MD 1248* Upper limit range 2 (a
2
) [100 units MS/s 2 ]
MD 1252* Upper limit range 3 (a
3
) [10000 units MS/s 2 ]
9.5.3.1 Installation without adaptation characteristic
The installation is carried out in two stages. In stage one, the friction feedforward
control without adaptation (MD 1804*, bit 6=1) is derived.
Two parameters (compensating amplitude and compensation time constant) can
be altered. These two parameters are each increased or decreased until the de-
viations from the programmed radius become minimal or have completely disap-
peared in the circularity test at the quadrant transition point (Figs. 9.20 to 9.24).
A starting value of a relatively small compensating amplitude (e.g. MD 1232* =
100) and a time constant of a few position controller cycles (e.g. MD 1236* = 80)
should be defined at the beginning of the measurement.
Changes can most clearly be seen when the circularity test is first carried without
friction feedforward control (MD 1804*, bit 6 = 0).
Fig. 9.20 shows typical quadrant transition points without friction feedforward
control.
9 Drive Servo Start-Up Application (as from SW 3)
9.5.3 Conventional quadrant error compensation (as from SW 2)
1) 100% in the two compensation values from MD 1232* and 1240* correspond to a speed setpoint of
1 V on analog drives and 10% of the maximum speed set on the drive side on digital drives.