Beginners guide to Command Control and DCC

Command Control & DCC

Beginners guide to Command Control and DCC

As you may have already discovered, controlling a model train is a rather simple matter. At the very basic level, all that is needed is two wires run to the track. This works OK for one train, but what if you want to control two or three? You can always build a block control system, but as your layout grows, this can become very complex and involved. There is another way

Command Control
The idea behind command control is simple. Rather than relying on voltage and polarity to move your train, there is a constant power level on the track, and the train has a decoder in the locomotive. The throttle sends signals to receiver, which interprets them as speed and direction controls. Like a television, the decoder ignores any signals that it is not tuned in to receive. This allows the modeler to have many different trains running on the layout without the need for large banks of switches.

Digital Command Control
In 1994, the NMRA began an effort to establish a uniform standard for command control that would allow many manufacturers to build DCC equipment that would inter-operate with each other. This has been a great success and has made a great deal of affordable command control systems available to the model railroad community.

Sounds great! What are the downsides?
Good question. There are two distinct challenges that the beginner will face when making the choice to go with DCC. The biggest challenge to the beginner is the fact that you will need to install decoders in all of your motive power. Newer locomotives, both steam and diesel, make this easy by providing a socket in the locomotive that a decoder plugs into. There are even some locomotives on the market that have decoders installed already! Unfortunately, most locomotives on the market will require the modeler to install the decoders themselves. This can be complex, and is not recommended for the beginner modeler. There are products that can help make the installation process easier. If you like a challenge, there are sites on the Internet that can provide very good instruction. Also, many hobby shops and private individuals provide installation services. This can be somewhat expensive.

This brings us to the other challenge: Cost. Decoders are available for less than $20 each, but even a small fleet of 6 locomotives represents a cost of $120. Many modelers feel that DCC is worth the cost, but it is a consideration. The throttles and command stations begin at $150 and increase up to almost $1000. A beginner has no need for a $1000 system, but as you can see, the price range is considerable.

OK, now that I know what to look out for, what next?
Well, The first step is to choose a system to buy. There are a number of systems on the market that are designed for the beginner. They all have subtle differences, and are mostly in the $150 to $300 range. Much like a new car, I recommend a test drive before you purchase any system at any price. This can often be done at your local hobby shop. If you don't have a shop close to you, then contact your local model railroad club and ask if they run DCC. Most clubs are happy to accept visitors and let them run a train. (Clubs are great resources for beginners anyway) If there is not a club in your area, then consider attending a train show in your area. There will be lots of dealers, regional clubs, and even some manufacturers that you can talk to and get your hands on the equipment.

There are also many online resources that can help you find people in your area who use systems that you want to look at. The next step is to choose either locomotives, or decoders. For a beginner, the best choice is to find a locomotive that has a decoder already installed. If you look for a locomotive or decoder that has an NMRA Conformance Warrant, you can be assured that the product has been thoroughly tested for conformance to the DCC Standard. Most decoders on the market provide the basics like motor control and headlights. More advanced decoders offer additional light options, and special effects like flashing lights and rotary beacons. Special features like this often require additional lights and details on the locomotive, and are not recommended for the beginner model. It does provide the beginner motivation to expand the modeling skills needed for such effects, as they can be stunning.

How about locomotives that don't have a decoder in them?
Some systems allow for the control of one locomotive that has no decoder in it. There has been much debate in the DCC community as to if this is a good idea. There are some motors used in model railroading that can be damaged by this. Almost all locomotives that a beginner would be interested in do not have these kinds of motors in them. A good rule of thumb is the cost of the locomotive. If you paid less than $150 for a diesel or less than $300 for a steam engine, you probably do not have one of these motors. If you are not sure, check with the manufacturer of the locomotive. Ideally, you should have a decoder in every locomotive you want to run.

OK, what about my layout?
For the beginner, all of the usual things apply for building the layout. Track needs to be straight and properly connected. If you can run a regular train around the layout, then you will not likely have a problem with DCC. As your layout gets more complex, there are some things that need to be addressed, but for a beginner, these things aren't usually a problem. If you would like to learn more about layout wiring for DCC, this website ( is a good place to start. This can get very complex, and should be approached with caution by the beginner modeler.

Anything else?
At one point, you will need to set up the decoder. This can be as simple as setting the address. The best way to approach this is thoroughly read the instructions that come with the system. If you run into trouble, don't be afraid to contact the manufacturer and ask questions. There is also a large DCC community online that loves to help beginners. Above all else, stick with it. There is no such thing as an unsolvable DCC problem.

Back To The Trains

Page last updated December 15, 2015