DCC Trains. What Are Configuration Variables (CV) On A DCC Model Railroad
Configuration variables are used to program decoders in a digital command control system. Their value ranges from 0 to 255 in binary or they can be operated as a bank of 8 binary on-off switches.
A CV can be manipulated to control addresses, lights and sounds. Its value is stored even when power is off. The standard set of CVs includes motor control, mode control, speed table, address, advanced consist and decoder identification.
CVs value can only be changed on the programming track, and not when the train is running. Some systems allow the command station and throttles to display CV values.