Tell a driver to wait until a trigger you select is touched by a train you
select (or any train)
The trains you can select are identified by their locomotive.
Give the locomotives in your session names, so you can recognise them.
The triggers in the layout must be named by the user before the command recognises them.
Don't give two triggers the same name, it could result in unexpected behaviour.
(For more info look into the readme.txt)