The shuttle module or ATC (Automatic Train Controller) MERG Kit 46, comes preprogrammed with a number of different configurations, selectable using an on board 4 way DIL switch. The track on this demonstration board is a symetrical arrangement that allows all of these configurations and the module cycles through these.
The track is Kato Unitrack, the points have integral motors using a two wire arrangement where the direction of current flow determines direction in which the points are set. The points here are driven by PD3s, MERG Kits 37a & 37b.
The ATC module has two track outputs designated 'End' and 'Intermediate'. For a simple end to end no other modules are needed, the two end sections are isolated in both rails and the 'End' output connected to these, the 'Intermediate' output is connected to the remainder of the track, observing correct polarity throughout.
For any configuration with more than 2 ends, some switching is required, this is achieved using the CSR4 (Cab Select Relay x 4) module, MERG Kit 46. This has 8 relays arranged in pairs providing a means of switching either of the ATC outputs or none (off) to each of 4 supplementary outputs. This gives provision for 4 stopping places or ends which may be at any one time off, end or intermediate.