Connecting a Computer to Your DCC System

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Summary: Connecting a computer to your Digital Command Control layout provides many benefits. The first and perhaps fastest noticeable benefit is programming of decoders. After your computer is connected to your layout, you will need some DCC Software. From decoder management to automation and operations software, the addition of a computer expands the possibilities of Digital Command Control.


Benefits of Using a Computer

You do not need to use a computer with your Digital Command Control system, this article explains the benefits of harnessing a computer's power and related software to enhance your enjoyment of DCC.

There are many benefits of connecting your computer to your DCC system. Perhaps the most noticeable benefit is for programming multifunction and accessory decoders. Using software, such as the free JMRI software suite, you can quickly and easily program decoders without learning all the complicated configuration variables of your decoder.

You can also perform automation of your layout, control signals automatically, as well as a display of your layout with train locations.

Of course, this does involve more wiring and more costs. For example, you will need to connect your DCC to your computer (see below). You will also need to setup up block detection so that your computer will know where trains are. If you are using a DCC system with transponding, some software applications can not only tell that a block is occupied, but with what rolling stock.

Connecting your Computer

You will need to connect your DCC system to your computer through a computer interface (find your system below). To do this, you will need to follow your systems documentation on throttle bus wiring.

USB Bridges

Most computers with a USB or serial port will be adequate. JMRI software is available for Apple's OS X/MacOS, Linux and Microsoft's Windows operating systems. Some interfaces may be USB only and if the computer lacks a USB port, a Serial to USB adapter may be the answer, or if possible, installing a USB interface card. There are issues surrounding older versions of MS Windows and USB, so some research may be needed prior to moving toward interfacing a computer to your DCC system.

Not all USB to Serial adapters are created equal. Some may not work correctly with the USB device or the serial port.

The typical 25 pin serial port uses almost all the pins, some for purposes other than data communications. The 9 pin version uses all the pins, so if some signals (such as DCD, CTS, DTR and DSR) are missing, it causes problems.

Digitrax DCS 240 with a USB interface

The best USB to Serial converters are based around the FTDI Chipset. ESU and RR-CirKits offer adapters which will work.

ESU offers a 1.8 USB connection cable, and warns that older ESU USB adapters may not work with Window7. It has both D-sub and USB connectors. It is USB 2.0.

Manufacturer:RR-CirKits|RR-CirKits offers a similar product with an adapter for 25 pin D connectors, should you need it.

Mac OS Big Sur

Apple has made internal changes to the MacOS Big Sur which have rendered the drivers for many USB to Serial fridges useless by deprecating their drivers. If you are contemplating upgrading to a newer version of the Mac OS, verify that the interface you are using is supported. Many third party drivers have not been updated. Some may never be.

This situation should improve during 2021 as vendors release updated drivers compatible with Big Sur.

Computer Interfaces

Consult the Computer Interface List for available devices compatible with your DCC system.

Multifunction Decoder Programmers


There are a number of specialized devices available that allow easier programming and updating of multifunction decoders. Some also offer the ability to load and manipulate the sound files, or update the decoder's firmware. They are standalone devices which do not require a command station or booster to function.

The LokProgrammer from ESU is an example of a programmer for ESU's decoders. As the more recent LokSound decoders can have in excess of 100,000 CVs to adjust, the Lokprogammer with its software can do this quickly and effortlessly.

Several other manufacturers, such as QSI, also offer devices to program their decoders.

Troubleshooting an Interface Device

A typical complaint is that the computer cannot find the interface to your DCC system. Frequently the culprit is a old device lurking in your operating system that is confusing your new device driver. To clean up old device drivers, search the web for, "removing old device drivers from <your OS>", then follow those directions.

NCE USB Issues

Many use an ESU cable built around the FTDI chipset with their NCE Power Pro. The UN8-BE from RR-CirKits is similar.

Counterfeit Devices

USB Bridges

Sometimes a USB to Serial interface does not work. One reason is that the USB interface IC (USB Bridge) in the adapter is a counterfeit. The most commonly counterfeited USB Bridge is the one developed by Future Technology Devices International. FTDI did update their drivers, and those drivers will not work with an IC not made by FTDI. In many cases the drivers for MS Windows 10 do not work with counterfeits.

If your generic USB bridge cable doesn't work, the most like reason is the driver from FTDI has disabled it. Contact your device's manufacturer for guidance.


Some material comes from the JMRI website. If you are interested in using the JMRI suite of tools, visit their website to see what you need. JMRI Website

See also