I've found it is much easier to have the alarm bits in the PLC to be contained in a DINT or INT tag/array. Then in ME you can setup the alarm trigger for that single tag, depending on the alarm bit(s) within that tag are active you just have to type in the appropriate alarm message. Easy as copy->paste.
So in the PLC you have a DINT tag called Alarm_Array with length of 20. Which would result in 640 alarm bits.
Alarm_Array[0]
Alarm_Array[1]
Alarm_Array[2]
.
.
.
Alarm_Array[19]
Each array would contain 32 alarm bits.
Alarm_Array[0].0
Alarm_Array[0].1
Alarm_Array[0].2
.
.
.
Alarm_Array[0].31
And so on.
In ME you can setup a single Alarm Trigger:Alarm_Array[0],L20 (L20 designates the number of arrays to look at).
Set the "Trigger Type" to bit.
In the Messages tab, the trigger for all alarms would be Alarm_Array[0],L20 The value would be 1 - 640 to correlate to the order of the alarm bits in the above array.
Set the messages up to match.
It's an easy way to get your alarm messages in ME, however you may have to re-write some PLC code.