External Alarms not activating
MB300 DO's were configured on External Alarm Configuration and as per Master Configuration Manual, MB300DO signals should not be configured for External Alarms instead DAT(B) object must be used.
Once we configured DAT(B) Objects on External Configuration, External Alarms started working.
Extract from Advant Master Configuration Manual:
The External Alarm function makes it possible to activate and deactivate an external alarm notification object in the controller. To prevent write conflicts when outputs are concurrently activated and deactivated, it is only supported to use object type DAT(B).