Siemens sinumerik 840D sl Function Manual page 426

Detailed description
2.2 Interface signals
2.2 Interface signals
Axisspecific signals
Despite assignment of an individual drive to several axes, the use NC/PLC interface signals
remains unchanged.
This requires explicit access coordination in the PLC user program.
As the same drive is being used, the same status signals from DB31, ... DBB92-95 are
displayed in all axes involved in the exchange.
However, control signals DB31, ... DBB20-21 must only be set in the axis with exclusive
control of the drive. The servo enable DB31, ... DBB2.1 is only effective for the set NC/PLC
interface signal:
DB31, ... DB24.5 (change setpoint output assignment)
Axes without the corresponding drive control are subject to functional restrictions and are
therefore operated in follow-up mode. For this purpose, the servo enables are deleted
automatically by the controller.
Diagram of the PLC program
The following example illustrates a possible setpoint exchange sequence.
10
Special functions: Setpoint Exchange (S9)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0