Siemens SINUMERIK 840C User Manual
Page 371
6 NC Machine Data (NC MD), NC Setting Data (NC SD)
04.96
6.7.1 Axis-specific MD bits 2 (axial bits 2)
Special case ”parking axis”
The axial interface signal ”Parking axis” also causes the interface signal ”Reference point
reached” to be deleted for an axis with SIPOS/Endat absolute encoder. When bit 3 of MD
1808* is set, a new referencing is suppressed. The absolute value is not transferred until
POWER ON.
Note:
Reference point approach can be carried out again when MD 1808* bit 3 is deleted.
Bit 3 Bit 3=1 The value NC MD 396* for the absolute value is valid.
Meaning for SIPOS:
After power-on the signal "reference point
reached" is set for this axis.
Distance coding:
The referencing procedure is performed with this
value and acknowledged with "reference point
reached".
Bit 2
To be able to calculate the machine absolute value after NC reset, it is
necessary to know whether the value of the absolute encoder (or distance
coded linear scale) gets larger or smaller as the machine absolute value
increases.
Bit 2=1 Machine system and SIPOS/Endat absolute system (or distance-coded linear
scale) are of opposite sense
Bit 2=0 Machine system and SIPOS/Endat absolute system (or distance-coded linear
scale) are of same sense
Bit 1 Bit 1=0 Absolute offset results from MD 396
*
Bit 1=1 Absolute offset results from MD 396
*
+/- 99 999 999
(+/- depends on sign of MD 396
*
)
Default value:0
Bit 0 Bit 0=1 The NC axis is equipped with an absolute encoder.
The absolute value is transferred on POWER ON for both measuring systems.
Caution:
When the control is being installed for the first time, you must perform
POWER-ON after declaring the encoder otherwise positioning errors will
occur!
7
6
5
4
3
2
1
0
Bit No.
NC MD
1812*
Sign
inversion
setpoint
master/
slave
2)
controls
master/
slave
2)
controls
master/
slave
2)
Master/
slave
operation
after Power
On
2)
Pos.-contrl.
follow-up on
error (as
from SW 5)
Adaptation
comp. time
const.
neural QEC
1)
Learning
phase
neural QEC
1)
Neural
QEC
1)
Torque compensation
controller
Bit 7
Sign inversion setpoint master/slave
Bit 7=1 With bit 7 it is possible to take account of different ways in which the master
and slave drives might be connected to the common output without having to
change the polarity and the direction of travel of the individual drives (MD 5640
bit 1 and 2). This bit only has to be set if, given a positive setpoint, the
axes/spindles would rotate in opposite directions at the mechanical coupling.
_______
1)
As from SW 4
2)
As from SW 4.4
6–186
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Siemens AG 1992 All Rights Reserved 6FC5197- AA50
SINUMERIK 840C (IA)