Siemens sinumerik 840d Programming Manual page 321

08.97
9
840D 840D
NCU 571 NCU 572
NCU 573
Additional notes
Setpoint coupling provides better synchronization of
the leading and following axis than actual value
coupling and is therefore set by default.
Setpoint coupling is only possible if the leading and
following axis are interpolated by the same NCU.
With an external leading axis, the following axis can
only be coupled to the leading axis via the actual
values.
Switchover between actual and setpoint coupling
A switchover can be programmed via setting data
$SA_LEAD_TYPE
You must always switch between the actual-value
and setpoint coupling when the following axis stops.
It is only possible to re-synchronize after switchover
when the axis is motionless.
Application example:
You cannot read the actual values without error
during large machine vibrations. If you use leading
value coupling in press transfer, it might be
necessary to switchover from actual-value coupling
to setpoint coupling in the work steps with the
greatest vibrations.
 Siemens AG 2000. All rights reserved
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) – 04.00 Edition
9.4 Axial leading value coupling, LEADON, LEADOF
810D 840Di
Path Traversing Behavior
NCU
Setpoint coupling
Ax1
Actual value coupling
NCU 1
Ax1
Actual value coupling
9
Ax2
NCU 2
Ax2
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