ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

DCC (Digital Command Control) the best thing since sliced bread for model railroaders

Updated on September 10, 2014

DCC (Digital Command Control) what is it?

Digital Command Control systems are used to operate locomotives on a model railroad. When equipped with Digital Command Control, locomotives on the same electrical section of track can be independently controlled.A DCC command station, in combination with its booster, modulates the voltage on the track to encode digital messages while providing electric power.Each locomotive is equipped with a mobile DCC decoder that takes the signals from the track and, after rectification, routes power to the motor as requested. Power can also be routed to lights, smoke generators, and sound generators. A stationary decoder can be attached to the rails to allow control of turnouts, uncouplers, operating accessories (such as station announcements) and lights.The great advantage of using DCC over traditional DC systems is the simpler wiring needed to operate more than one locomotive at a time. Before, to operate more than one locomotive independently, the track had to be wired into separate "blocks" with switches selecting which controller powered which block of track. If an operator failed to switch control of a block before his locomotive entered, a short circuit or loss of control was possible. With DCC, many layouts can be wired as a single large block, and each operator can control his locomotive without worrying about crossing a block boundary.

The DCC Guide: How to Select and Use Your Command Control System
The DCC Guide: How to Select and Use Your Command Control System

I read this book before choosing my DCC system.


Books about DCC (Digital Command Control) on Amazon

Basic DCC Wiring for Your Model Railroad: A Beginner's Guide to Decoders, DCC Systems, and Layout Wiring
Basic DCC Wiring for Your Model Railroad: A Beginner's Guide to Decoders, DCC Systems, and Layout Wiring

I own this book, it was the first book I read when I was about to convert my DC block layout to DCC.


I used to be a DC (Direct Current) guy

I used to be a DC (Direct Current) guy, I used the traditional method of controlling my HO Scale locomotives by breaking my track layout into block sections. Each block section was electrically isolated from other block sections that could be controlled from the main control panel. By electrically isolating each block section I could indiviually control each locomotive running on each block section. This method worked, and was used for many years before the dawn of affordable DCC (Digitical Command Control) systems but it required a lot of throwing switches to control each electrical block. Plus it was not very realistic as your where essentially controlling the track not the locomotive itself. It also required a lot of electrical wiring as you can see from the picture.

The Digitrax Big Book of DCC
The Digitrax Big Book of DCC

Great book if you chose Digitrax for your DCC system.

DCC Projects & Applications
DCC Projects & Applications

I reference this book often for new ideas for my HO scale layout.


Some Important Information

Before continuing I need to instill in you some important information:1. All DCC (Digital Command Control) systems, no matter what manufacturer, encode the exact same signal format on the track. This format was standardized by the NMRA the National Model Railroad Association which actively creates standards for the model railroad industry.2. Since the signal format on the track is the same for every manufacturer of DCC (Digital Command Control) systems per National Model Railroad Association standards, you can mix and match decoders manufacturer brands and they will all work with your Digital Command Control system. For example you could purchase a Digital Command Control system from Digitrax and purchase decoders from Atlas and these components will work together.3. You cannot mix and match DCC (Digital Command Control) systems. For example, a Digitrax DCC system will not be able to communicate with an Atlas DCC systems or the other way around. Each manufacturer of DCC systems uses its own protocol or communcation standard for communication between DCC components. The National Model Railroad Association is only concerned that the digital signal on the track is standardized.

My first DCC (Digital Command Control) system

I purchased the Zephyr Command Control System. This was a basic DCC (Digital Command Control) system offered by Digitrax. I purchased the Zephyr command control system because:1. This Zephyr Command Control System was inexpensive. 190.00 on Amazon. This is a major factor when you have a family and little funds.2. The Zephyr Command Control System is expandable. You can purchase other components to link your computer to the Zephyr Command Controls System. In addition, you can purchase a booster which will allow you to control more DCC decoder equipped locomotives. The Zephyr Command Control System has a limited 2.5 amp output which will probably allow you to control about 5 or 6 locomotives at one time.3. The Digitrax web site was professional, informative, and it instilled in me confidence in their products and support.4. The Zephyr Command Control System was "Made in the USA" how often do you see those words?

Zephyr Command Control Starter Set on Amazon

DIGITRAX, INC. Zephyr Xtra Starter Set DGTZEPX
DIGITRAX, INC. Zephyr Xtra Starter Set DGTZEPX

I own the Digitrax Zephyr Xtra Starter Set. It is a great beginner set and I don't think my layout will outgrown it anytime soon!


Installing a decoder in a DC (Direct Current) locomotive

Being on a small budget for my model railroad hobby, I decided to retrofit a DC (Direct Current) locomotive with a decoder. A basic Digitrax decoder (model DH123D) can be had for under $20 from most hobby stores and I already own several DC (Direct Current) locomotives. A good DCC equipped locomotive can be close to $100. Beware of the term "DCC Ready" this means that the locomotive is setup to accept a plug-in DCC decoder board but does not come equipped with one. The Digitrax DH123D comes with a detailed wiring diagram and instructions.

Installing a decoder in a DC (Direct Current) locomotive (Continued)

The Digitrax DH123D decoder wiring was pretty straight forward. All I did was follow the wiring diagram that came with the decoder. The DH123D decoder has outputs for controlling forward and reverse lighting so I hot glued LEDs (Light Emitting Diode) in the locomotive shell to be used for forward and reverse lights. Note: Unlike incandescent light bulbs, LEDs are polarity sensitive and they also need a 1K current limiting resistor wired in series with them. The DH123D decoder comes with a detachable wiring harness. I recommend disconnecting the decoder from the harness while soldering the harness wires in place. Once all of the wiring harness wires were soldered to the right connection I used a dab of hot glue to keep the wire harness in place. I then attached the DH123D decoder, it is the blue object in the picture labeled "DH123' in gold.

Digitrax Decoders for Sale on Amazon

I only purchase Digitrax Decoders for my layout since I use the Digitrax Zephyr Command Control system to run my layout. After all, how helpful will Digitrax support be if you have a problem with a locomotive that has another brand's decoder installed?

Testing the Zephr Command Control System

Note: You need to purchase or retrofit a locomotive with a DCC (Digital Command Control) decoder before testing. I chose to retrofit an old HO locomotive with an decoder for testing purposes. The decoder is an electronic part that is in each DCC (Digital Command Control) locomotive that allows the DCC (Digital Command Control) system to control each locomotive separately on the same track without having to electrically isolate the track sections into blocks like in a standard DC (Direct Current) system. You will notice I have two track sections in my test setup. The long track is for testing the DCC equipped locomotive, the short one is for programming the DCC decoder in each locomotive.

Testing the Zephr Command Control System (Continued)

In order to run several DCC (Digital Command Control) locomotives on the same track you need to assign a unique ID to each one of the locomotives. The Zephr Command Control System (like all Digital Command Control systems) superimposes a digital signal on the track along with the power to run the locomotive(s). In this digital signal there is an ID. Only the locomotive with the ID encoded in the digital signal will respond to the request made from the Zephr Command Control System. Digital signals encoded on the track may tell a locomotive with a specific ID to move forward, move in reverse, stop, change speed, turn on/off sounds or turn on/off lighting. The commands recognized from the Zephr Command Control System depends on the decoder installed in the locomotive. Some basic decoders only recognize signals to control direction or lighting while the more expensive decoders have the ability to play sounds through a small speaker installed in the locomotive. I like to put a small sticker on each decoder equipped locomotive to identify its ID number.

Programming a decoder equipped locomotive

By default, all Digitrax decoders have the ID number of 3 assigned to them. You need to change this to a unique ID number for each locomotive. If all locomotives have the same ID number of 3 you will not be able to control each decoder equipped locomotive separately and they will all respond to the same commands from the Digital Command Controller system. For the Digitrax Command Control System you program the ID by putting the decoder equipped locomotive on a separate programming track and enter the proper keystrokes on the Digitrax Command Control System to make this programming change. Note: There are many other parameters you can program into the decoder including custom speed tables and special lighting effects. Programming these parameters is out of the scope of this Squidoo Lens.

Running your locmotive on a DCC equipped layout

Not many modifications are needed to convert your DC block layout to a DCC (Digital Command Control) Layout. Simply disconnect your DC Transformer and connect your DCC System. Make sure all of your isolated electrical blocks are switched so that they received power and embedded digital signal from your DCC System. Never connect your DC Transformer and your DCC system to track at the same time. This could cause damage to your DCC system.. I am still in the testing phase so I have not yet attached my Zephyr Command Control DCC system to my DC block layout yet.


DCC (Digital Command Control) systems offer so much more flexibility in running your model railroad then the convention DC block system. With a DCC (Digital Command Control) system you are controlling the decoder equipped locomotive itself rather then controller power to the track where the desired locomotive you want to control is currently located. In addition, DCC (Digital Command Control) systems offer the ability to control lighting and sound that was never available under a conventional DC block layout system.The Zephyr Command Control system is a low-cost, expandable system that will allow you to get started in using DCC (Digital Command Control) to control your model railroad locomotives.

My Guestbook

    0 of 8192 characters used
    Post Comment

    • profile image


      7 years ago

      Good basic introduction to dcc!!

    • Laura Schofield profile image

      Laura Schofield 

      7 years ago from Chicago, IL USA

      Great lens - I've got 3 boys and they all love trains. They've got a few model sets and I'll have to get them working on this sort of set up, I think they'll love it!


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)