Skip to main content

JMRI Hardware Guide: Digitrax DCC

LocoNet Connections

JMRI, including DecoderPro and PanelPro, works with your Digitrax command station to program decoders. To do this, it communicates with the command station over the LocoNet using one of several types of LocoNet adapter.

DecoderPro will work with all the following command stations:

To connect your computer to the LocoNet, and hence to the command station, you need one of the following adapters:

Generally, any of these can be used with any type of computer to communicate with any type of command station. Currently, the LocoBuffer-USB and PR3 are the recommended solutions. The LocoBuffer II and original LocoBuffer are no longer being actively produced; their only advantage now is that they use a traditional serial port rather than USB. The MS100 is not recommended; it sometimes fails to provide reliable communications, and cannot be used with JMRI if you are using MacOS X or on most Windows Vista machines.

The Uhlenbrock Intellibox can also be controlled directly through it's serial port; there's a separate page on how to do this.

PR2 and PR3 Programmers

JMRI can also use a Digitrax PR2 or PR3 to program and test decoders. The PR2 is a stand-alone unit which does not connect to the rest of the layout, the command station, nor to a LocoNet. For more information on using a PR2 with DecoderPro, please see the PR2 setup page. The PR3 can either serve as an interface (see above) or as a stand alone programmer. There is more information on the PR3 setup page.

Setup

To connect your computer to a Digitrax DCC system, you need a  LocoBuffer-USB, PR3, LocoBuffer-II, LocoBuffer, or MS100 to act as an adapter. See below for more information on these. The LocoBuffer-USB is highly recommended.

Note that except for the PR3, these are only LocoNet interfaces, not stand alone programmers like the Digitrax PR2 and PR3. None of these except the PR3 will let you read CVs if you have an Empire Builder! For that you need a Chief or Zephyr command station.

  1. Connect your adapter to the LocoNet, and connect your computer to it with the appropriate serial or USB cable.
  2. Mac and Windows users should install the proper USB drivers if they are using USB devices.
  3. Linux and Mac users should be sure that the correct Java communications packages have been installed.
  4. Open a JMRI program and go to the "Preferences" panel. This normally opens automatically the first time each program is run, or you can select it from the "Edit" menu.
  5. Select "LocoNet LocoBuffer-USB", "LocoNet MS100", or your device from the top selection box. You can then select the proper serial port in the second selection box. Check in your system hardware information if you are not sure which port to select.
  6. The baud rate box will be fixed and grayed out if you've selected LocoBuffer-USB, PR3, or MS100. There are two speed choices for the LocoBuffer and LocoBuffer-II; select the one that corresponds to the jumper settings on your LocoBuffer unit. We recommend that you start with the 19,200 choice for the LocoBuffer or LocoBuffer-II; see the LocoBuffer-II and LocoBuffer pages for more information.
  7. The fourth box should be left on "hardware flow control" unless you later consistently get a message about the LocoBuffer control leads being improperly set up, in which case you might want to try to bypass that by selecting "no flow control". This box will be blank if you've selected LocoBuffer-USB, PR3 or MS100.
  8. In the fifth box, select the type of command station you have. Note that this program can't read decoder CVs if you have an Empire Builder (DB150); that's due to the Empire Builder hardware, and there's nothing we can do about it.To read CV's in conjunction with a DB150 use the PR3 in programming track mode.
  9. The series of radio buttons labelled "GUI style" allows you to select how the program will look. "Metal" is the native Java look available on all types. Other choices will vary with your computer type. "Motif", "Windows", "MacOS" and "MacOS Adaptive" look native on Linux, Windows, MacOS "Classic" and MacOS X respectively.
  10. In the bottom selection box, you can pick the default programmer format. You can override this each time you open the programmer, so this is here just for convenience. If you are the primary user of this system we suggest you set this to "Comprehensive".
  11. Click "Save". You'll be asked if it's OK for the program to quit, click "Yes".
  12. Restart the program. You should be up and running.

If you are going to control turnouts, signals or other devices on your layout from JMRI or another program, we recommend that you set the command station's "Meter route/switch output when not in trinary" option off. (T) When on, this option greatly reduces the number of commands the LocoNet can handle each second, which can cause significant delays when you're controlling signals, etc. To turn it off, you can use the "Configure Command Station" tool in the LocoNet menu to set Option Switch 31 to "T" (thrown), or set it directly in the command station using a Digitrax throttle.

Using JMRI with LocoNet

There are a number of pages that discuss how to use JMRI with LocoNet:

Of course, the DecoderPro and PanelPro JMRI applications work very well with LocoNet.

Network Connections

There are several methods available to connect multiple computers to a single LocoNet. These communicate via standard TCP/IP protocols, and can even work remotely. For more information ...

Limitations

PR-1 not supported - Note that DecoderPro cannot directly program decoders via a PR1 programmer. You have to use one of the command stations above.

MacOS X and the MS100 - Because MacOS X can't communicate at the special baud rate used by the MS100, the MS100 won't work with MacOS X. You should get a LocoBuffer-USB instead.

Microsoft Vista and the MS100 - It has been reported that Vista does not support the special baud rate used by the MS100. If you find that your MS-100 does not work on your Vista machine you should get a LocoBuffer-USB or PR3 instead.

Uhlenbrock Intellibox - The Intellibox has two LocoNet connections, called LocoNet-T and LocoNet-B. The LocoNet-T connection can drive more devices, but does not provide the Rail-Synch signals that some LocoNet devices (particularly the BDL-16, -162 and -168) require. A LocoBuffer should be connected to the LocoNet-T connection.

Debugging

Digitrax Manuals