If an irregular program or system status is detected, DAMP outputs brief diagnostic information to SYSOUT and then terminates with a dump (user dump).
If, however, task switch 30 is set and DAMP is executing in interactive mode, a message is issued asking whether a dump should be generated.
If task switch 30 is set and DAMP is executing in batch mode, no dump is generated.
If you suspect an endless loop in DAMP, you should interrupt DAMP by pressing the function key 
. The rest of the run can be controlled with the INFORM-PROGRAM command (see the description of “Entering DAMP statements via the system command INFORM-PROGRAM” on "System level"). Entering /INFORM-PROGRAM MSG='?' switches to SDF user guidance mode, and entering /INFORM-PROGRAM MSG='*DUMP' terminates the program with a dump.