How DCC works
Commands are sent digitally to decoders
How Digital Command Control works in a sentence: Digital Command Control works by combining the output of a power supply with digital instructions telling the locomotives and other accessories what to do, directly onto the tracks. Decoders, which are in fact small computers (or micro controllers), respond to instructions addressed to them. The decoders are installed in locomotives, or are larger stationary devices that can control signals and switch machines.
The important concept is that a DCC system is applying a pure digital signal on the track. There are no high frequency carriers or audio tones present on the track, as were often employed by earlier analog command control systems.
The alternating digital signal contains not only the address and the instructions, but also supplies the power needed by the decoder and motor.
Read more to learn about Digital Command Control and how it can enhance your layout.