6.1.2 Digital Command Control

 DCC is short for DIGITAL COMMAND CONTROL. It is not just another method of control, it is a standard for manufacturers to use to make their products compatible with other products on the market that meet this standard. There are a number of manufacturers of DCC systems, Digitrax, NCE, Lenz, MRC and CVP are a few of the larger manufacturers.

DCC System components.

The DCC system consists of a number of components necessary for operations. These components are identified in their own web pages.

6.3.1 Command Station 6.3.2 Power Station (Booster) 6.3.3 Command Buss 6.3.4 Throttles 6.3.5 Decoders 6.3.6 Sound Systems 6.3.7 CVs

DCC is a technology jump over the Analog systems in the past. In DCC, the track voltage remains the same. The DCC signal is a bipolar square waveform, which contains digital information. Long pulses are zero and short pulses are ones. The frequency does vary between 8kHz-10kHz depending on the information sent. 

With DC operation and a standard DC power pack you are essentially running your trains by adjusting the voltage to the track. With DCC there is constant voltage on the track and you are controlling your train through signals passed from your throttle through the Command Station and Booster(s) to a computer chip (decoder) in your locomotive which controls how much voltage the motor will receive and its direction. Speed and direction is unique to your locomotive, and independent from all other locomotives. Direction is controlled by the throttle and is independent of which direction the locomotive is placed on the track; forward is forward and backward is backward.

Most DCC systems provide for walkaround control which allows you to walk with your train around the layout, staying where the action is. Walkaround throttles can be tethered or wireless.  

Since decoders are essentially computer chips they can be programmed (to the extent a particular decoder is equipped with the capability) to provide many different lighting and sound effects. As well as directional headlight and rear lights some lighting effects include ditch lights, Rule 17 headlights, MARS-type lights, beacons, strobe lights, etc. All are under control of the function buttons of the throttle running the locomotive. 

Prototype realistic sound can be added to locomotives through decoders designed for sound. Some sound decoders are sold with sounds for a specific prototype locomotive while others offer a custom sound download feature. In all cases separate adjustment of each sound feature is provided to enable customization — volume and effects. Prototypical operation of a locomotive's horn/whistle and bell becomes possible.

The WWSL

I have run layouts with DC and DCC. For the WWSL ver 3.0 I wanted to have the following operator experiences:

• I wanted to run a train, not manage the track the train ran on. 
• I wanted walkaround control.
• I wanted independent control of lights and sound.
  

I first read about EasyDCC back in 1997 when Keith Gutierez published several articles about the system in Model Railroader. It impressed me as being a simple, yet full featured system and that impression stuck with me over the years.