Hi RoboFanatuc ,
Yes, the program can get terminated by a few things. If your CSTOPI is set to abort ( typically in MENU/SYSTEM/CONFIG ) then a pulse on this signal will terminate a running program in its tracks. You could also have a background supervisory program running at the same time that calls the ABORT or ABORT ALL commands. The robot is capable of multi tasking and running a seemingly hidden program at the same time as your main one. Check the UOP inputs and also look at the CSTOPI specifically.
Hope this helps !