Associations link two related trains together, and appear in the timetable and reference the RID of both trains.
When a train splits or joins en-route, or when the next working for that train is known, there will be an association in Darwin between the two trains. Associations are not necessarily present for every train schedule.
There may be more than one association on a train, in which case there will be more than one association message for that train. The location at which the association occurs is identified by the working time arrival (WTA) of the main train.
<Association tiploc="CLCHSTR" category="NP"> <main rid="201501231641459" wta="22:52" pta="22:52" /> <assoc rid="201501231641462" wtd="22:56" ptd="22:56" /> </Association>
There are three types of association: