Digital Command Control

DCC "Friendly" Definitions

Reference: "DCC Readiness: Comprehensive Decoder Installation Standards," by Ron Beardon, N-Scale Magazine, November/December 2006, P. 47.

A locomotive that is purchased with a decoder already installed.

This sounds simple, but it isn't. Some locomotives can be purchased with or without a decoder; when you purchase them with a decoder already installed then you may consider them decoder equipped. This type of locomotive is not what this definition means.

DCC Equipped means a locomotive is universally DCC equipped — they all come that way; you cannot purchase them without decoders. The decoder contains auto-sensing circuitry to determine if the locomotive is being operated on analog (DC) or DCC track. The locomotive should operate equally well on either analog or DCC.

Athearn N Scale steam locomotives (4-6-6-4 and 4-8-8-4) and most new Bachmann Spectrum locomotives (e.g. Acela Express, HHP-8, USRA Heavy 4-8-2 and 40-Tonner) are DCC equipped.

The term Plug-and-Play (PnP) comes from computer usage. Plug a device into a computer, the computer will install the necessary software drivers and the device can be used within a very short time. This idea can also be applied to installing DCC decoders in locomotives.

DCC Plug-and-Play means you can install a decoder without taking the mechanism apart at all — the decoder "plugs" in. There are two ways of meeting this definition. The first is the use of the NMRA 8-pin socket in the locomotive where a decoder with an 8-pin plug is simply plugged into the socket. The second way is the removal of an existing analog circuit board and replacement with a decoder, provided you do not have to remove any screws or solder any wires.

Examples of the circuit board change are many Kato N Scale diesels. Locomotives with NMRA 8-pin sockets include some Con-Cor locomotives such as the most recent PA-1, the USRA 2-10-2 and 4-8-4's.

A DCC Ready locomotive is a close cousin of the PnP locomotive in that a ready-made decoder slips into the chassis, but in this case some disassembly is required. Note that in the PnP definition no disassembly at all is required.

DCC Ready means the locomotive is one for which there is a drop in decoder that usually requires only a screwdriver to install. If any wires have to be soldered then it is not truly DCC Ready.

Several manufacturers make drop in decoders. Many locomotives are DCC ready. Most Atlas locomotives made since 1999 and Kato cowl-body locomotives (E8, P42, F3/7, F40PH), as well as others are DCC ready.

Even though there is no decoder that merely plugs in, installation is fairly easy. In many cases the motor is already or easily isolated from the frame, and all the needed wires are fairly easy to get to. Some trimming and soldering of wires will probably be necessary, but there will be no cutting or milling of the frame required.

DCC Friendly means the motor is easily isolated from the frame and all the needed wires are readily available.

In this category decoders are normally hard-wired into the locomotive. However, any circuit boards that may be dropped in, but which require soldering of any wires (such as the headlight) would also fall in this category.

Examples would be current Model Power steam locomotives, InterMountain FT/F3/F7 A-units and some of the older Life-Like diesel locomotives.

It should be noted that some locomotives that strictly meet this definition — no cutting of the locomotive — are more difficult. Wires may not be color coded. Some brass locomotives and earlier steam locomotives are examples.

You can install a DCC decoder into a DCC capable locomotive, but it is going to take some work. The work may require cutting metal, routing wires and soldering. It will always require isolating the motor from the frame, which may not be quick and easy.

DCC Capable means any locomotive for which a decoder can be installed that does not fall into one of the previous definitions. With the small size of currently available decoders there are not many locomotives that cannot be decoder equipped.

Two companies produce products that help with installing a decoder in old locomotives with a split metal frame. Such locomotives would be considered DCC Capable in our definitions above since a good deal of frame cutting is required. Atlas, Life-Like and Kato use Zinc alloy frames that are very tough to cut.

If you disassemble your older locomotive and send the frame plus a fee to Aztec Manurfacturing in Reno NV they will mill the frames for you and return them. You still do the wiring and soldering, but the hard work of modifying the frame has been done for you.

Southern Digital in Atlanta has copied the stock frame, then makes castings out of a pewter-type alloy that weighs about 30% more than the stock frame. However, this frame, called a Digi-Frame, is softer than the original frame and thus must be handled carefully so they do not bend during decoder installation.

Full details and contact information for the Aztec and Southern Digital frames are provided on the Installing Wired Decoders page on this site.

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Last updated: Saturday July 4, 2009

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