DCC for Beginners

If you are new to DCC and are wondering what it is all about, this section is for you. It is aimed towards someone that knows nothing about DCC and is intended to answer some basic questions you may have about DCC. Many of the answers below will direct you to other sections of this website for additional information.

We think you will find the question and answer format of this webpage helpful. Just look for your question.

Many thanks to Don Vollrath and Marcus Ammann for answering many of the questions below.

Introduction

Modern electronic gadgets are truly complex in the manner in which they work. Practically everything now days is operated by a computer of some sort. But using them does not have to be complex. That's a process of us fundamentally understanding enough about how it works from the outside, so that we can get it to perform the intended tasks. However, connecting up several gadgets and getting them to work together can be a problem. “Plug & Play” is an attractive buzzword, but often we can’t even tell if the separate components are really designed to work together. For that we need to know much more about how each device is supposed to operate, and how those characteristics may affect the interface to and operation of other equipment. The education process leaves much to be desired as available literature or published information is either too simplified or too complex for the intended audience. The viewpoint of the assistance may even be slanted toward product sales rather than universal usefulness. This leads to customer / user frustration rather than satisfaction.

DCC Vs DC for model train control is one of those topics. There are some big differences between the methods, but many of the fundamentals are still the same. The small details are the cause of all the discussion, confusion and problems for some users.

In a nutshell, what is DCC?

DCC stands for Digital Command Control. It is a system where digital commands are sent to the locomotives through the rails. The layouts of yesteryear used block control. Each required its own power pack and a complex control panel to keep each locomotive electrically separate from each other. DCC allows independent control of multiple locomotives within the same block.

DCC provides for digital control of turnouts and signaling as well. Other features include a multitude of sounds, block detection, momentum control, and the ability to lash together locomotives.

DCC is an NMRA standard. This means locomotives equipped with decoders from various manufacturers may be used with any DCC system!

What are the basic components of DCC systems? In short, what do I need to buy to get started?

A DCC system consists of five basic components:

Command Station – The heart or brains of DCC. The Command Station is a dedicated computer that communicates with all other parts of the DCC system. Selecting the brand and model of Command Station is key to selecting the type of Throttle controls as well as feature expandability of the system.

Throttle or Cab – The man-machine interface between You, the engineer, and the Command Station controlling the train. Various Throttle equipment styles exist. Some systems use a plug-in, walk-around Throttle, with the possibility that more than one can be used at the same time. Some systems have Throttles built into the Command Station. Each brand of DCC system requires their own brand of Throttle or Engineer’s Cab, and their specific type of Throttle to Command Station wiring interface. You cannot easily intermix brands here.

Booster – A power amplifier of the communication signals from the Command Station into power applied to the track. Some starter systems combine a Command Station and Booster into one box. Almost all Boosters require an external Power Supply. The ampere rating of the Booster and Power Supply will limit how many locos you can run at the same time. Some Boosters are in a separately available box and may be controllable from a Command Stations of a different brand.

Power Supply – An AC transformer or DC power source for the Command Station and track power Booster. The Power Supply is NOT INCLUDED with many DCC equipment systems and must be purchased separately. An additional Power Supply is usually required with each additional Booster.

Loco Decoder – An electronic receiver inside the loco out on the track. The Decoder receives communications from the Command Station and controls the loco motor and lighting effects. Some Decoders also add locomotive sounds to operation. Every DCC controlled locomotive must have its own decoder. But any brand of Loco decoder should work with any brand of DCC Command Station / Throttle equipment.

Many home layouts are easily accommodated with starter systems that include the above basic items, plus a few additional Loco Decoders. [But be sure to ask about the Power Supply.] However, as your model railroad grows you may want more DCC equipment, including: additional Throttles for multiple users (same brand); remote Plug-In panels for walk-around Throttles; Accessory Decoders for DCC operation of track switches (turnouts); Auto-Reversing track controllers; more Power Supplies & Boosters; Electronic Circuit Breakers for separation of track circuits into multiple power districts; or even Radio equipped Throttle Adapters.

Note that a computer is NOT required. Computers are only needed for signaling or a few of the do-it-yourself DCC systems. NONE of the commercial systems require a computer and therefore, no programming is required. The only thing you need to do is configure the address of your locomotives.

How is it supposed to work?

For standard DC controls, the ‘throttle’ puts variable voltage power on the track. Loco motors and headlights connect directly to the track. The speed (and intensity of the lights) will vary by simply changing the voltage applied to the track. Electrical current (amperes) drawn by the loco flows through the track rails and feeder wires. More than one loco can be operated on the same rails when coupling them together (mu’ed) but since they all receive power through the same throttle, they will all run at the same speed (when geared the same). If you want to operate more than one train independently of another, you must break up your layout into multiple control blocks (power districts) where each has its own operator and throttle. It is unlikely that the feeder wires and/or rails will need to carry more than 1 or 2 amps (HO scale) at any given time. Furthermore, since an operator is watching the trains and controlling the throttle, he often adjusts the track voltage setting to get to the desired running speed. This unconsciously compensates for all kinds of electrical sins that causes problems with DCC. (Poor electrical connections, resistance in the track rails and feeder wires, power supply sag with load, etc. etc.)

DCC puts ‘fixed’ electrical power on the track. There is a special receiver (the decoder) inside each loco that receives track power AND listens to commands sent out over the rails from a master control station (command station). These gadgets are actually small dedicated computers and electronic hardware. The DCC track voltage is an amplified computer to computer serial communication link bit stream, manipulated by the control station and beefed up by the ‘booster’ to have enough power to operate motors and lights out at the train. The whole reason for DCC is to allow multiple locos to operate independently on the same track, without having to divide up the layout into complicated electrical control blocks. The DCC communication scheme allows this to happen. Power for operating the locos still must come from the track, but all of the track can now be electrified in unison. This does simplify track wiring on most layouts. However, power from the DCC booster must be able to reach and operate all the moving locos simultaneously. This means that track wiring for DCC may need to be more robust than that for DC.

What’s so different about the wiring?

Another complication is that the DCC voltage on the rails is AC rather than DC. However, this is not quite the same as the smooth cycle constant low frequency 50/60 Hz AC available at the local utility wall outlet. The command station to loco communication scheme relies on relatively fast reversals of track voltage to be detected at the loco decoder. It is the timing of these transitions that form the serial bit stream of computer to computer communications. If the decoder in the loco cannot correctly read the commands, DCC does not work. This means that short power interruptions to the loco caused by poor electrical connections or dirty track previously ignored by DC throttle systems can cause major havoc with DCC. Another subtle difference becomes important on larger layouts. As power wiring between booster and track becomes longer than 30-40 feet, the inductance of track power wiring can become more significant than the electrical resistance. A track voltage loss and voltage ‘ringing’ occurs as the DCC signaling scheme attempts to quickly reverse track voltage. This causes a voltage drop at the track and possible loss of DCC signaling even though the measured DC resistance of the wiring may be low. Using a larger wire gage on the DCC bus or track feeders does not necessarily help this problem. Twisting the DCC bus wires to lower the inductance, or moving the booster to utilize shorter wiring runs, or providing another booster closer to the track will help.

For more information, see the section on track wiring.

Do I need blocks with DCC?

Theoretically, you do not need blocks as in the traditional sense. You will need blocks if you are using block detection or polarity reversing sections such as wyes, balloon tracks, and turntables.

While you don’t need any more blocks than this, if you have a layout that will be operated by more than one person or a layout bigger than might fit on a sheet of plywood, it is recommended that you install additional blocks to ease troubleshooting. You don’t need as many as you had with a traditional DC-powered layout, but without at least a few blocks, you will not know where to start if you have a problem. Furthermore, if you have a short on a DCC layout, the whole layout may shut down without blocks.

For more on the topic of blocks, see the section on track wiring.

Are DCC system components interchangeable?

The only thing that the NMRA made standard was the DCC signal on the track. That means all locomotive decoders as well as stationary decoders for controlling turnouts and signals are interchangeable. You can use any of these devices with any DCC system that supports the use of such devices. (Some starter systems do not support turnouts and signals.)

Some boosters are interchangeable with command stations of a different manufacturer. I’m not sure why you would want to do this. If you think you will be saving money, just keep in mind if it doesn’t work, you might have trouble getting help from the manufacturer of either system or others on the Internet. To ensure you don’t have any problems, you should stick with boosters made by the same manufacturer as your command station.

In general, throttles are not interchangeable with command stations manufactured by someone else.

Note: Some systems, especially the starter systems, may have a throttle, command station, and even a booster integrated into one unit.

How do I select a DCC system?

It is impossible to recommend a DCC system. You have to pick the system that is right for you. Here are some suggestions on how to do that.

Dale Gloer suggests:

In my opinion the "best" system to buy is one that has a good, helpful dealer near you. A second criteria is to chose a system that your modeling friends use. After the above criteria, your choice can be based on functionality and price. Dale.

Mark Gurries suggests:

The best way to choose which system to buy, of course, is to try them all first by going to a friends, hobby shop, or RR club. You may be able to simplify the list if you have a strict budget, but trying some of the higher end systems can be educational. Look at the throttle and see how it feels in your hand, Select and run a train, make and break a consist and program a locomotive on the programming track. Ask yourself, is this an easy thing for me to remember or easy to find in the manual in case you had to do a quick look. Check out the manuals too. Borrow one [or download from manufacturer’s website] and take it home to read and see if it all makes sense to you when you get back and try the system. Be honest about your abilities. For example, if you cannot set a digital clock, you may want to lean towards a simpler system with fewer features. Another issue is learning curve. If you are going to run your layout once a month, a system that forces you to re-read the manual to use it is not going to be a very enjoyable experience. Another factor, as Dale indicated, is to look at what your friends use in term of support. But if you think your going to have to bug your friends every time you want to play with YOUR layout at home, then that system may not be a good system for you. The best DCC system is the one that works best for you.

And finally, my thoughts:

You may want to buy the same system as your friends; especially if you will have operating sessions. This will allow you to use each other’s throttles.

When selecting a system, especially a starter system, make sure it has the features you want. If you want sound, make sure the system supports functions that will trigger your sounds. If you want to use your locomotive number as its address, make sure you get a system that supports long addressing. Does it support consisting? Can it control turnouts? Will the system be able to grow with your needs or is it not expandable? Check eBay and see how much you will be able to sell your starter system if you outgrow it.

Ask Dale or Mark a question on the Wiring for DCC Q&A Forum.

Can I use DCC on my existing layout?

If you have an existing layout, you may be able to use it as is. Most of the advice given in this website is aimed at giving you trouble-free operation. Minor problems that you tolerate with DC may give you major problems with DCC. This is for two reasons. One, if you have multiple operators, a minor problem may affect all operators simultaneously giving you major headaches. This might happen when your booster shuts down. The second reason is that DCC systems are capable of putting much more current onto your track. This can cause melted plastic parts and pitting of your track and wheels from arcing.

The most important thing you need to do to determine if you can use your exisitng wiring is to hook up your booster and give your entire layout the "short test." See the section on track wiring for more on this test. When running this test, flip all your turnouts. All the manufacturers insist that your layout be able to pass this test. Being able to pass this test will avoid melting and arcing.

Do I have to solder all my joiners?

It is not recommended that you solder all your joiners together. For more on what to solder, see the section on track wiring covering this topic.

Reversing Basics:

If you have a wye, a balloon track, or a track plan that loops back on itself, you will have a short circuit. In order to deal with this situation, you will need some way to avoid the short circuit. This is accomplished by designating a section of track as the reversing section and you will usually need an automatic reverse section controller or simply call it a reverser. In addition to needing a reverser, you will need to use insulated joiners at both ends of your reversing section.

If you have a turntable, you will also need a reverser. If you have a balloon track, you may be able to use a relay which is less expensive than a reverser.

Whether you use a relay or a reverser, they are pretty simple to hook up. Usually two wires feeds the reverser from the mainline or non-reversing track. The reverser then feeds the reversing section by two wires.

Example of a balloon track using a relay to accomplish the reversing function. You don't have to use a relay - you can always use a reverser.

For more on reversing, see the reversing section in the section on track wiring.

What happens to a train when the power reverses in an automatic reversing section?

The train continues to proceed in the direction it was heading! This is one of the great things about DCC. Train direction is always independent of the polarity of the power. When you command a train to go forward, it goes forward no matter what.

When a train enters the reversing section (right), the track power reverses. The locomotive that is already in the reversing section (left) continues going in the direction it was already headed.

Let me guess, you next question is, if the train doesn’t care about track polarity, why do we even need to worry about reversing sections? Look at the next two diagrams.

As the train crosses the gap, the wheels on the red rail continue on a new red rail. The same is true for the blue rails. This is good.
As the train crosses the gap, the red rail goes to a blue rail. On the opposite side, blue goes to red. This is a short. This is bad. Without reversing section control, your booster will short out and your train will come to an unceremonious stop.

With reverse section control, you make sure red goes to red and blue goes to blue. Automatic reverse section control detects the shorted condition above. Rather that shutting down your booster, it automatically reverses the track’s polarity to get rid of the short so that red goes to read and blue goes to blue. Pretty nifty, huh?

One last question. What happens when two trains enter a reversing section at the same time? This is bad, too. The diagram below shows two trains entering a reverse section. The train on the left has no short. The train on right causes a short and the automatic reverse section controller flips the polarity of the track. But wait, doing this now causes a short with the train on the left. No matter which way the automatic reverse section sets the track polarity a short occurs. When this happens, your booster (or electronic circuit breaker if you are using one) shuts down your track power. Lesson: You never want two trains entering a reverse section simultaneously at opposite ends.

For more on how to wire up reversing sections, go to this website’s section on track.

Can I control my turnouts with DCC?

Yes, you can. You can even have the turnouts report the turnout status to a central computer. You can use this to operate signals or control train movements.

You can control your turnouts with push buttons or from your throttle.

For more information, see the section on turnout control.

What is a DCC friendly turnout? Why do I need it?

"DCC friendly" is a term coined by this website in 1996. Other websites and companies have given it other names. Essentially, it is a turnout that will cause you the least amount of problems with a new DCC layout.

There is nothing magic about a turnout being DCC friendly. The term was coined when a layout was converted to DCC and we had a lot of problems with the turnouts. In an old block control system, a short at turnout only inconvenienced one operator. In a DCC system, multiple trains may come to a stop irratating a lot of people.

When a trains shorts out on a turnout, the problem could be the turnout's fault or the trains. The points on the turnout may be too close or any of a multitude of things could be wrong with a locomotive or rolling stock. In an ideal world, you would fix the turnout, the rolling stock, or the locomotive. This can be a real challenge if your layout is not in a climate controlled room. Temperature and humidity can make perfection an unattainable goal.

DCC friendly assumes a certain amount of pessimism - you will never be able to get all your turnouts and rolling stock in perfect condition. Some of us are good at mechanical tinkering. Most of us are not. DCC friendly is simply a mechanical approach to masking a problem many of us are not very good at solving.

You don't need a DCC friendly turnout. But if all your turnouts, locomotives, and rolling stock are not in perfect shape, than you might want to consider DCC friendly turnouts.

For more information, see the section on turnouts.

LOCOMOTIVES

Can I have sound?

Absolutely! You can have all sorts of sounds! While DCC is not required to have great sound, great sound arrived shortly after DCC. DCC does provide for the control of sound that previously wasn't possible. You can control the whistle, bell, dynamo, blow down, coupler clanking, horns, dynamic breaks, and the diesel engine. Plus you get the fireman shoveling coal, air compressor, oiling and more.

You can buy sound systems to add to your locomotive or you can buy locomotives that already have sound built in.

For more information, see the section on sound.

Can I run a regular DC locomotive on a DCC layout?
Can I run a DCC locomotive on a regular DC layout?

Some DCC systems allow you to run a regular DC locomotive. You will only be able to run one locomotive this way. You will have to use "address 0." A few DCC systems allow you to run a regular DC locomotive, but they require that you add a few parts to the locomotive to make it work. A regular locomotive will buzz when used on a DCC layout without a decoder in it. For some motors, using them on a DCC layout without a decoder can be harmful to the motor. I suggest that you only use address 0 on a regular DC locomotive to try the locomotive out. Don't use a regular DC locomotive on a DCC layout as a long term thing. You will also find that you cannot use a regular DC locomotive on a DCC layout that has autoreversing. The locomotive will learch into reverse when the autoreverse activates.

Some locomotives equiped with decoders can be used on regular DC layouts. Some will work, but you must set a jumper inside the locomotive. Other decoders must have a CV set to enable or disable the ability to run on DC. How can you tell if your locomotive will work this way? Read the instructions that came with your decoder or locomotive if it came with a decoder in it. You can always put your decoder equiped locomotive on a regular DC layout and see if it runs. You won't hurt anything by trying.

What is a CV?

CV is short for Configuration Variable and these are the decoder's microcontroller adjustable parameters that are used to determine how the decoder's outputs (motor, lights etc) perform and setting it's address. Once a CV is adjusted it is remembered even when power is removed. A few examples are the address, CV 1 - short and CV 17 & 18 - long address and CV 2 that is used to set the first (start) speed step. All decoders have the basic operating CVs and other CVs that may be unique to that decoder. Refer to decoder's instruction manual for all associated Configuration Variables.

Adjusting the CVs is what the DCC manufacturers call programming (bad term, makes DCC sound difficult like computers and it isn't) is usually done by giving a decimal value between 0 and 255 for most CVs, see manual.

The manufacturer has entered default values for each CV that enables the decoder to run a loco without any adjustment (programming). To address this decoder you must select "3" the default value for CV 1, the short address. The decoder can be reset to default values. For independant running of locos, all locos decoders must have a different address.

Does DCC have momentum control?

Yes, in two flavors. The standard DCC decoder in each loco has separate settings for acceleration and deceleration rates that allow you to easily simulate the slow starting and stopping action of a fully loaded freight train or the faster throttle-brake response of an unloaded switch engine. The NMRA has identified adjustments for this feature at CVs 3 and 4. However, each decoder manufacturer may interpret the meaning of a specific numeric setting in their own way, so different brands and models of decoders may not operate the same way in all (14, 28, 128) throttle step modes. The user must determine the ideal setting for a given engine – decoder - load combination.

Another momentum–like feature is that most DCC systems will allow the user to select a loco, get it moving, and keep it running at the same speed setting indefinitely while the cab throttle is unplugged or a different loco is selected and operated from the same cab. The throttle "memory" is ideal for following a train around a plug-in walk-around layout.

What is DCC Ready?

A DCC ready locomotive is one that has the wiring from the wheel pickups, motor and the lights terminating at a socket, in the case of HO - 8 pin, N - 6 pin and O - 2 times 4 pin sockets. The loco will run on DC due to a jumper plug being inserted from the factory to connect applicable sockets to the motor and the lights. When the loco is to be operated on a DCC layout, it is as easy as removing the body shell, removing jumper plug and inserting the decoder plug, no soldering. This set up removes all the hassles of soldering all decoder wires to the relevant points and thus saves time and any one can do even with no DCC or soldering experience. If the loco runs but lights do not work, then reverse the orientation of the decoder plug. No damage will be done to either decoder or loco if plug and socket are wired as per NMRA standard. Apart from a loco coming with "DCC equipped" with decoder, this is the next best thing. Any brand DCC decoder will enable motor and all functions to work correctly. Pin 1 is identified with a small triangle pointing to the pin. Specific decoders for certain locos will fit in perfectly and have correct current ratings for motor and lights.

DCC Ready, as used by Bachmann in their G-scale locomotives, means something different. It simply means that it will be less work to install a decoder than if they had not made it "DCC Ready." But it still may be a lot of work. For an example of a Bachmann DCC Ready locomotive, consider the installation instructions for their external-frame Consolidation. If you are new to DCC and not confident of your wiring ability, you may not want to tackle a Bachmann as your first project. Bachmann provides no instructions other than "see the instructions for your decoder" - which are obviously generic. For specific instructions, see this and other websites. I have not worked on any other G-scale locomotives claiming to be DCC Ready to know how DCC Ready they are.

How do I know if a locomotive already has a decoder in it?

Installed decoder: When purchasing a loco with a decoder installed, the dealer or an advertisement may say the loco is "DCC equipped" or "Factory installed decoder" or "W/DCC" or something along the lines but NOT "DCC Ready".

No decoder fitted: If stated "DCC ready" there is NO decoder fitted but wiring inside loco is terminated with a socket, ready for addition of a "Plug and Play" decoder. This is an easy installation, no soldering.

If loco is of unknown DCC status then the following can be done. On a DCC system, place loco on the program track and see if command station can read CVs, if unable to, then no decoder. Also if no decoder fitted, the loco would hum with throttle at "0"
On a DC system if loco responds to the throttle then two possibilities 1. NO decoder or 2 may have a decoder that has analogue operation enabled.

What are speed steps?

To operate the motor in the loco, the decoder has to provide a varying voltage from min to max value. In 14 speed steps there are only 14 different values of voltage, 28 has 28 values and 128 has 128 values. These values are called speed steps. Depending on the type of decoder some speed steps can be adjusted to modify a linear speed curve. Options on some decoders for speed step adjustment (speed tables) can be volts Start, volts Mid and volts Max, internal user selectable speed tables, manual adjust of speed steps CV 67 - 94 for 28 speed steps and external computer adjustment to these CVs to adjust motor performance, to enhance loco especially slow speed operation and to match different mechanisms to have the same performance.

14 speed step decoders are basic early units and may cause jerky motor operation.

How can I get good low speed control?

Decoders have a few CVs that can be adjusted to fine tune the motor performance, especially better slow speed control. The basic adjustment of CV 2 is Volts Start.Adjusting this enables the loco to start moving at the first speed step. Adjusting CV 5 - volts max will reduce maximum speed and adjusting CV 6 - volts medium will now change the linear voltage table to non linear, that is reducing the value of CV 6 will give smaller increases in speed in the first half of throttle rotation, (flatter speed line). Later model decoders have the added feature of dither, torque compensation or back EMF (manufacturers names) to further improve slow speed control, by modifying the pulses of current to the motor to overcome inertia and mechanism friction.

Some decoders have selectable speed tables that have their speed steps in such a manner to alter the linear speed table to have more or less throttle travel at low or high speeds, refer decoder instruction manuals. When a speed table has small increments at the low end and larger increments at the high end, this makes for better low speed control. Speed tables can also be manually loaded or the use of a computer with a program like Decoder Pro connected to the command station.

The use of speed tables and CV2, CV5 and CV6 enables you to speed match locos to perform the same, irrespective of the mechanism. Some sound decoders do not support CV5 and CV6.

I don't intend to have many locomotives. Why might I want long addressing?

It's not a matter of how many locos you have, it can only be a few, long (4 digit) addressing is used so that users can address their locos by it's road number. If you had a loco with a road number of 5305, using the short (2 digit) address you have to
remember which of the two digits to use, and visitors would have a bigger problem. Easy to address any loco, just use the actual road number.

What is "Back EMF" and Speed Stabilization?

Back EMF (electromotive force) is a feedback method used by some decoder manufacturers to provide a constant speed of the loco irrespective of grade of the track. or load without adjusting throttle. This is a form of "cruise control" for locos.
Therefore when the train comes to a hill it would maintain the same speed going up the hill as on the flat.

How many trains can a throttle control?

This depends on the throttle. You will have to look at the manufacturer’s literature or website. One or two is typical. Some throttles and systems support consisting. This allows several locomotives to act like one and thus, counts as one.

Which decoder is right for my locomotive?

The Wiring For DCC Q&A Forum gets this question a lot. But we can rarely provide an answer. Given all the locomotives out there and decoders that are available, it is unlikely that one of us has installed a specific decoder into the same locomotive you have. New models of decoders come out all the time. So what do you do? Luckily, there are easy solutions.

1. Visit your local train store. Make sure you take your locomotive with you. One of the key things is to make sure the selected decoder will fit.

2. Call stores that specialize in DCC equipment like Tony's Train Exchange. They carry decoders from several manufacturers and they know what the current models of decoders are. They sell decoders all the time. They may indeed know which decoder is best for your particular locomotive.

You might as well contact your favorite store and ask them which decoder is best for you. Right after they answer your question, the next thing you will want to do it buy it! So even if we knew which decoder is right for you, you will need to contact your favorite store anyway.

Selecting a decoder is fairly easy. The main thing is to find a decoder that fits in your locomotive. If your locomotive has a decoder socket, as many newer models do, you will want a decoder with a plug on it. Make sure the decoder has the features you want. Unless you buy a budget-minded decoder, most decoders will have the features you need like four-digit addressing.

There are many features a decoder can have. I could describe them here, but that may not help you in determining what you need. You may not know what you need or want. To make things simple, don't buy a budget-minded decoder and buy one that fits with a plug on it if you need it. As you learn about what features are desirable, a non-budget-minded decoder will likely have what you need.

One more thing. Many locomotives, particularly diesels, have decoders made just for your particular model. Diesels are tight for space so DCC manufacturers are providing decoders just for the particular model you have. Check your favorite DCC manufacturer's website and see if they have a decoder just for you.

Do you have a beginner question not covered above? Ask it on the DCC Q&A Forum.