Fires whenever a data segment in a transaction set is read.
The 'callback' is called when the 'Segment' event is emited.
The argument 'e' has the following properties:
e.tag e.name e.loopName e.fullSegment
The Segment event will fire when a data segment is read. The Tag parameter contains the tag of the segment. Name contains the name of the segment as defined in the associated transaction set schema. LoopName contains the name of the loop or group this segment is present in (such as N1Loop1).