Why does the DSE 7120 MK2 (and other 7000 series controllers) stop button LED flash?

From the DSE 7120 MK 2 operators manual:

"In the event of an electrical trip or shut-down alarm, the module displays the Alarm Icon and the Stop/Reset Mode button LED begins to flash."

Therefore the Stop LED will flash in the event of an electrical trip or shutdown alarm. If the controller is, for example, being programmed on the bench and doesn't have its plugs attached, the emergency stop would not be connected and this would count as a shutdown alarm - meaning the light will flash.