Autonomous Singleaxis Operations - Siemens SINUMERIK 840D Function Manual

6.3.2

Autonomous singleaxis operations

Functionality
Single PLC axes, command axes started via static synchronized actions or asynchronous
reciprocating axes can be interpolated independently of the NC. An axis/spindle interpolated by
the main run then reacts independently of the NC program with respect to:
● NC stop
● Alarm handling
● Program control
● End of program
● RESET
Boundary conditions
Axes/spindles currently operating according to the NC program are not controlled by the PLC.
Command axis movements cannot be started via non-modal or modal synchronized actions for
PLC-controlled axes/spindles. Alarm 20143 is signaled.
Transfer axis control to the PLC
Description of the sequence
1. PLC → NC: Request to control the axis
2. NC: Checks whether the axis is a main run axis or a neutral axis.
3. NC: Checks whether an additional axis may be controlled from the PLC.
4. NC confirms the transfer:
– DB31, ... DBX63.1 = 1 (PLC controls the axis)
– System variable $AA_SNGLAX_STAT = 1
Result: The PLC controls the axis/spindle.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
DB31, ... DBX28.7 = 1 (PLC controls axis)
6.3 Motion behavior and interpolation functions
P2: Positioning axes
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