Digitrax's “safety selection” is an important operational safety feature. Digitrax chose not to allow one way address selection to prevent multiple operators from being able to select and send commands to the same addresses at the same time. Having multiple operators sending commands to the same address can result in serious problems in an operating session because locos can appear to be out of control.
Simplex radio throttles like the DT402/R, DT400/R, DT300/R, UT4/R and similar throttles operate as one-way (simplex) infrared or radio transmitters. The DT402, DT400/R, DT300/R, UT4/R must be plugged into LocoNet to select an available locomotive address to run on the throttle.
After an address is selected on your DT402/R, DT400/R, DT300/R or UT4/R, you can unplug from LocoNet and run the selected addresses with infrared or simplex radio without having to plug in again unless you want to select another loco to run.
The throttle will automatically convert to infrared or radio operation for all speed, direction, function, operations mode programming, and switch commands.
Digitrax tetherless throttles must be plugged in to LocoNet to program locomotives on the programming track and to set up and break up consists. DT402/R, DT400/R, DT300/R and UT4/R can be set up to prevent release of loco addresses unless the throttle is plugged in to LocoNet.