MrTrains Railroading

With DCC installed on a simple layout we basically have three components that make up the system. The command station connects to the track, the throttle is used to control trains, and a decoder is placed inside the locomotive to receive commands from your throttle.

The picture below shows how the components connect to a simple train layout. This layout is a loop of track with a passing siding. This would be typical of a basic train set you could purchase as a gift from your local hobby shop.

Transformer - Starting at the wall outlet we first plug in a transformer. The transformer takes the power from the wall outlet and transforms it into manageable power our model trains can use.

Command Station - The DCS100 command station is the “brains” of the operation. The command station provides power to the track and sends signals to our locomotives. To install the command station we will take the two wires from the wall transformer and plug them into the appropriate terminal on the Digitrax® Command Station.

Note the two lines labeled Track Power Rail A and Track Power Rail B. These are wires from the command station that provide the power to run the layout. It doesn’t matter which rail is A or B, we can pick any one we want. Though, once we decide which rail is A and which is B rail we have to stick to it across the entire layout.

Controller (throttle) - The hand held controller has the knobs you use to control the speed and direction of your locomotive. The hand held controller plugs into the DCS100 by a telephone cable, this cable is known as the LocoNet cable on Digitrax® systems. Generally speaking this cable can be referred to as the "command bus" on the layout. The DCS100 listens to your hand held controller via the command bus and then sends your commands to the track.

Decoder - The final component you need is a decoder installed into your locomotive. The decoder is a component that is installed in your locomotive which receives commands and makes the locomotive do what you want it to do. The breakdown is like this;

• You send a request to change the direction of your locomotive on your hand held throttle.
• The command travels to the DCS100 via the LocoNet “telephone” cable.
• The DCS100 takes your command and sends it out to the layout via the Rail A and Rail B wires.
• The decoder in your locomotive picks up the command off the rails and then changes the direction of your locomotive.

This chain of events happens millions of times a second as we use the DCC system. When you send a command to your locomotive it seems almost instantaneous. Now why are we using DCC? Unlike our first Conventional Power example where only one train can run at a time, under DCC we can run up to 255 trains on our little layout as long as we have a decoder in each locomotive. No additional wiring is necessary to run all those trains.

This is a very simple start to the world of DCC but even the longest journey starts with but a single step. Enjoy!

- Mark N. Goedert