A15: ???

What is this instruction for???? And why?

My first guess would be that it is moving a value into a block of data that is read by a master PLC or HMI for alarm indication.

Yes, the bit before says "PROBLEM HAS OCCURRED ON INPUT MODULE D". I am guessing that there is a list of alarm messages stored somewhere, on of which says "A PROBLEM HAS OCCURRED ON INPUT MODULE __", where the blank is filled in by moving the value stored in A15.27 to N10:33 (probably a "4" for the 4th Input Module D.

Thanks Guys.