Siemens SINUMERIK 840D sl Function Manual page 799

Alarm handling for single axes
Alarms with an axis parameter are only displayed and not handled as single axis alarms. It is
sufficient to acknowledge these so-called "show alarms" with CANCEL.
Note
Only alarms that have to be cleared again with AXRESET take effect on single axes.
Use Case 1
Cancel operation of axis/spindle
The function Cancel axis/spindle corresponds to the current behavior of the channel-specific
NC/PLC interface signals:
DB21, ... DBX6.2 (delete distance-to-go)
Use Case 2
Stop axis/spindle
All axis motions controlled by the main run are stopped, thereby interrupting the following
movements:
● Axis/spindle:
● Overlaid movement such as:
Description of operational sequence:
● PLC requests the NCK to stop the relevant axis with NST:
● NCK brakes the axis along a ramp.
Extended Functions
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Note
The axis/spindle must be operating under PLC control. This supplementary condition
basically applies to all applications: Use cases 1 to 4.
The exchange of signals at the VDI interface during autonomous single operations is
described by means of machine axis 1 in a comparison of PLC actions as the NCK
reaction in Section "Control by the PLC".
For further information about channel-specific VDI signals, please refer to:
References
/FB1/ Function Manual, Basic Functions; Various Interface Signals (A2)
PLC axis, asynchronous reciprocating axis or command axis started by static
synchronized action. Following axis motion of the axis/spindle is not stopped.
$AA_OFF,DRF handwheel traversal or online tool offset and external zero offset.
DB31, ... DBX28.6 ("AxStop, stop") == 1.
Positioning Axes (P2)
Motion behavior and interpolation functions
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