Speed Step Controlled Acceleration in HO Scale WAP4 Locomotive Model with Loksound 5 Decoder 

In DCC, acceleration is set by CV3 and results in a constant level of acceleration, irrespective of throttle changes.
Acceleration in Tap Changer equipped electric locomotives, such as WAP4, is controlled by the increasing the notches from 0 to 32 while managing traction motor current within permissible limits. To best simulate throttle based acceleration, a custom acceleration logic was built for Loksound 5 decoders that gives the user 3 levels of acceleration based on how fast the speed steps are increased. This video demonstrates its operation.
Locomotive: Scratch built Indian Railways HO Scale WAP4 electric locomotive equipped with a Loksound 5 DCC decoder
Live Scaled Speed displayed using a Boulder Creek Engineering RollBy Speedometer