089

Review the program structure and count the nesting levels from main program through all M98 subprogram calls.

Identify which subprograms are calling other subprograms and map out the call hierarchy on paper.

Restructure the program to reduce nesting by consolidating subprograms or moving repeated code to shallower nesting levels.

Verify maximum nesting depth allowed in parameter 3107 (if accessible) and ensure program stays within this limit.

Modifying parameters requires proper authority and machine builder documentation

Search all subprograms called by M98 and verify each has a corresponding M99 command before the program end.

Check that M99 appears on its own block without conflicting commands and is not inside conditional skip blocks that prevent execution.

Verify no M99 P-address commands are creating unintended jumps that bypass proper return sequences.

Run the program in single block mode to identify exactly where the nesting depth increases abnormally.

Ensure machine is in a safe position with spindle/axes disabled during testing

List all M98 P-addresses in each subprogram and check if any subprogram calls itself or creates a circular reference chain.

Trace the program flow starting from the point where the alarm occurs to identify which M98 call triggers the circular reference.

Remove the circular call by redesigning the program logic or using a main program loop with conditional branching instead of recursive calls.

Test the corrected program in memory or dry run mode to confirm proper subprogram call sequence and returns.

Always perform dry run testing without workpiece loaded first