The PULSE on it's own can memorise up to 80 tyres across 5 vehicles of up to 16 tyres each.
Used standalone the PULSE can be programmed for the Tractor Unit and up to 4 Trailers. Once programming is completed the driver would simply turn on whichever of the 4 trailers they were towing (or any combination in multi-trailer situations).
To automatically enable the Drop & Hook mode you use the V2 GWY installed on the vehicle J1939 network. With a Universal Repeater (V2 also) each trailer and the PULSE on the Tractor unit the system will automatically 'drop and hook' between any trailer without further configuration.