Meaning of "Alarm source is implicit"

Hello all,

We have an 800xA for MOD300. The event collector service gets me an event like that: "Alarm source BB5601S is implicit." We have a lot of those from different signals. We realize the alarm is active from the same signal almost at the same time when this event appears. What is the meaning of this event message? What exactly does the event collector service mean to me?

There are two redundant pairs of connectivity servers but only one pair have the event collector service.

Thank you to all.