I recently, finally, dove into DCC at home by buying a Digitrax Zephyr Xtra and a Digitrax PR3. I’ve had a number of decodered locomotives for the significant amount of time I spend “visiting” or on NTRAK layouts, so I was familiar with the basic concepts, but had never got it running at home. Here’s what I did, because I didn’t find any nice, concise, step by step, walkthroughs, and I figured people my appreciate one.

Here’s what I started with to make it all happen.

  • Mac Laptop (mine’s a Macbook Pro Running OS 10.6.4) or desktop.
  • Digitrax Zephyr Xtra (Aka: DCS51). This is the command station that provides the “Loconet”.
  • Digitrax PR3 and included USB cable. This is what interfaces between your computer and “Loconet”.
  • Loconet Cable. This is, essentially, a network cable for Loconet devices. Don’t be fooled, it’s just a six wire (not four wire, this is important) phone cable. I got mine at a local electronics shop, but they can be had in many places, including Amazon.com.
  • JMRI. This is the application that talks to Loconet on your computer. It’s written in Java, which means that while ugly, it will work on many different platforms, including Windows Machines and Macs. It’s Free and Open Source, but you’ll definitely want to kick them a few bucks to support the project (and its past legal issues with a jackass patent troll). Don’t be a stereotypical cheap model railroader here, these guys deserve a little money for all the work they’ve put. You’ll want to download the latest Production version.

Step 1: Open everything up and plug it in.

This is an easy one, open everything up, the Zephyr, the PR3, and the Mac.

First setup your Zephyr. I’d suggest everything’s working fine there before moving on to the next step. Use it as it’s suggested, run some stuff, etc…

Then, using the Loconet cable, connect the PR3 (either Loconet port is fine) and the Zephyr (again, either port is fine). You should now see the status lights on the PR3 blink intermittently. Please note, you do NOT need to use a power source for the PR3, for our uses it’s self powered.

Now, using the USB cable, plug the PR3 into the Mac. It’s going to say something like “new network connection found, usb/cu.something”. Just hit ok and ignore it. You’re now all connected.

Step 2: Set up JMRI

There are a number of ways to do this once you’ve got JMRI setup, but the I usually do it by opening DecoderPro. DecoderPro is the application that lets you program decoders. Once the small screen is open (that says “DecoderPro” and has the two programming mode buttons), click the “Edit” menu, then select “Preferences”.

Now, configure JMRI to talk to Loconet. Create a new connection if one doesn’t exist. Use the following settings:

  • System manufacturer: Digitrax
  • System connection: LocoNet PR3
  • Settings:
    • Serial port: “/dev/cu.usbmodem1d11″ or something similar. You want the one with the “cu” in it.
    • Command station type: “DCS51 (Zephyr Xtra)” This is important, chosing the wrong one will make things look right, but won’t be.
    • Connection Name: “LocoNet”

Hit save, and it will ask you if you want to shut down JMRI to restart it. You do. Once it’s closed, relaunch JMRI, and you should be connected and ready to go. If you’re not, check this thread on the JMRI user group, because there is, for a short while, a patch that needs to be applied when using the DCS51.

Step 3: Test JMRI

Now that everything is setup, give it a test. From the same “DecoderPro” window as above, select “LocoNet”, then “Monitor Loconet”. This is an extremely helpful window that lets you watch the traffic on Loconet (it is a network, after all), and is a great troubleshooting thing to see what’s going on. When you click “start logging”, you will then be able to see all the commands being sent back and forth. It’s actually pretty fascinating to watch, but you’re here to run trains, so let’s go do that.

From the DecoderPro main window, select “Tools”, “Throttles” then “New Throttle”. This will open up a throttle window. Select a locomotive, or enter the address of one and hit “Set”. You should now be able to control your locomotive from the on screen controls.

Step 4: WiThrottle for Droids, iPhones and other Apple mobile devices.

Ok, so being able to run a train from your computer is nice, but you can’t carry a laptop around the layout room. You CAN use a mobile device to do it though. Once you have JMRI working, it’s incredibly easy.

Get the “Engine Driver” app from your App Store. The Droid version was free, but I’ve heard there’s a paid version. Either way, it’s gonna save you a bunch of money.

From the main JMRI window, select “Tools”, “Throttles”, “Start WiThrottle”. Now, fire up your app. As long as you’re on the same wireless network as your computer, you should see it advertised. Select it. Now select a locomotive, or enter a decoder address, and you’re ready to go.

Additional Reading

The JMRI Yahoo! Group is incredibly active and helpful. If you have questions, ask there!