What is a decoder?
Used in DCC, this device is placed inside a locomotive. It receives the signal being sent through the rails from throttle, and then translates the signal to the motor. It looks like a tiny PC board, and works much like the receiver in a R/C car. The difference is that instead of radio waves, the locomotive receives commands through the rails. However, there may be many locomotives on the layout, each receiving its own command from a different throttle. The decoder picks out which signal is meant for it, and disregards the others.
Decoder technology has been the preferred irrigation control technology in Europe for two decades. Decoder systems use a single pair of wires to operate a number of stations with individual decoders connected along a two-wire path. Each decoder is its own small waterproof control unit that is separately addressable with both power and signal sent over the same pair of wires. Decoder systems offer many benefits to both the installer and operator. First, less copper wire and associated labor reduces cost and simplifies troubleshooting. Repair of damaged cable is simple in the extreme compared to multi-wire. In addition, stations can be easily added in the field after initial installation, without digging in new wire back to the controller. Best of all, decoder systems are easy to operate. User operation of the ICC with decoders is identical to that with multi-wire modules fitted. Only in troubleshooting are diagnostic facilities slightly different. At installation, each decoder is quickl
