There is no "Overflow Trap" bit in Logix5000.
Logix500 was the only platform that ever had it, and to be honest, I can't see much use for it.
If you had an overflow somewhere in your program that set the trap bit, then it should have been dealt with at the time it occurred, not at the end of the scan. By then the overflow may already have caused mayhem.
Logix5000 will not Major Fault on math overflow at the end of the scan.