Sinumerik Alarm 12640 Channel %1 block %2 invalid nesting of control structures

Sinumerik Alarm 12640 Channel %1 block %2 invalid nesting of control structures

Parameters:
%1 = Channel number
%2 = Block number

Definitions:
Error in program run: Opened control structures (IF-ELSE-ENDIF, LOOP-ENDLOOP etc.) are not terminated or there is no beginning of loop for the programmed end of loop.Example:LOOP ENDIF ENDLOOP

Reactions:
– Alarm display.
– Interface signals are set.
– Interpreter stop
– NC Start disable in this channel.

Remedy:
Correct part program in such a way that all opened control structures are also terminated.

Program Continuation:
Clear alarm with the RESET key. Restart part program