Trains4Africa
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DCC

DCC (Digital Command Control)

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..DCC

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.

History:

A digital command control system was developed (under contract) by Lenz Elektronik GmbH of Germany in the 1980s for two German model railway manufacturers, Märklin and Arnold (models). The first digital decoders that Lenz produced appeared on the market early 1989 for Arnold (N) and mid 1990 for Märklin (Z, H0 and 1; Digital=).[1] Märklin and Arnold exited the agreement over patent issues, but Lenz has continued to develop the system. In 1992 Stan Ames, who later chaired the NMRA/DCC Working Group, investigated the Märklin/Lenz system as possible candidate for the NMRA/DCC standards. When the NMRA Command Control committee requested submissions from manufacturers for its proposed command control standard in the 1990s, Märklin and Keller Engineering submitted their systems for evaluation.[2] The committee was impressed by the Märklin/Lenz system and had settled on digital early in the process. The NMRA eventually licensed the protocol from Lenz and extended it. The system was later named Digital Command Control. The proposed standard was published in the October 1993 issue of Model Railroader magazine prior to its adoption.

The DCC protocol is the subject of two standards published by the NMRA: S-9.1 specifies the electrical standard, and S-9.2 specifies the communications standard. Several recommended practices documents are also available.

The DCC protocol defines signal levels and timings on the track. DCC does not specify the protocol used between the DCC command station and other components such as additional throttles. A variety of proprietary standards exist, and in general, command stations from one vendor are not compatible with throttles from another vendor.

 

Only 2 Wires!

The digital system uses only two wires for transmitting orders to the layout, the track. We can control locomotives, turnouts and signaling.

The track voltage is different from an analog model railroad, and uses digital packets to control the device (train, turnout decoder)