Sinumerik Alarm 16943 Channel %1 action %2 ALNX not possible due to ASUP

Sinumerik Alarm 16943 Channel %1 action %2 <ALNX> not possible due to ASUP

%1 = Channel ID
%2 = Action number/action name

The action in the 2nd parameter was rejected, since an asynchronous subprogram is currently active. Currently, only the integrated search run is rejected with this alarm. The integrated search run is activated, if search run is triggered in the Stop program state. In other words: Parts of a program have already been executed and a following program part is “skipped” with search run in order to continue the program afterwards. The event is not possible if the program is stopped within an asynchronous subprogram or if an asynchronous subprogram had been selected before the event. An asynchronous subprogram is selected, when the triggering asynchronous subprogram event arrives, but the asynchronous subprogram cannot be started (e.g. the asynchronous start program is not started because of a read-in disable or because the Stop key is active). In this case, it is irrelevant whether a user ASUP or a system ASUP has been triggered. User ASUPs are activated via FC-9 or via the fast inputs.
The following events lead to system ASUPS:
• Mode change
• Overstore on
• Aborting subprogram level
• Switching on of single block, type 2
• Setting machine data effective
• Setting user data effective
• Change skip levels
• Dry run on/off
• Program test off
• Correction block alarms
• Editing modi in Teach
• External zero offset
• Axis replacement
• Delete distance-to-go
• Measuring

– Alarm display.

Repeat the action after the end of the asynchronous subprogram.

Program Continuation:
Clear alarm with the Delete key or NC START.


  1. Siemens Diagnostics Guide by Siemens
Sinumerik Alarm 16943 Channel %1 action %2 ALNX not possible due to ASUP