As I’ve stated in previous posts, sound decoders have drastically changed my approach to DCC consisting. In an ideal world, I want all movement controls (forward, reverse, braking, dynamics) within a consist to be controlled by a single throttle, and I want only the lights, horns and bell of the lead unit to respond when an operator selects these functions. Digitrax’s “universal consisting,” unfortunately, doesn’t allow function-controlled movements like braking to go to the entire consist. Also, if you reverse the direction of the consist, you have to rebuild the consist to control both movement, lights and sound with the new lead unit. This is not a big deal for trains that only run in one direction, but every single one of my trains is an “out and back” where the lead unit of a consist switches, sometimes several times in a session. Asking operators to rebuild the consist every time they switch the train’s direction is not ideal.

Moving to “advanced consisting” (decoder-aided consisting) solved many of these problems but not all. Using the “consist” tab in JMRI, I was able to use the directional lighting features built into my Soundtraxx Tsunami 2 decoders to set the lights on the end units in a consist to “respond to consist address” but only in forward or reverse, thus solving the challenge of only getting the end lights in a consist to illuminate. The horns and bell, however, cannot be set to only operate directionally using the consist controls, so I was stuck with picking one loco in the consist to respond to all the horn and bell commands… this works, especially if all units use the same horn type, but it bothered me a bit to hear a Nathan M5 from the trailing GP35 instead of the Nathan P3 from the leading GP38. When I posed this question to a group of Digitrax experts, one of them pointed me to this video from Soundtraxx where someone had figured out how to use “alternate sound levels” function in the Tsunami 2 decoders to get directional horns, so I had to give it a try. The video left a few steps out, perhaps because they were using “simple consisting” (same address), so I had to experiment a bit to figure out how to make it work with advanced consisting, but in the end, I was able to get the consist to perform [almost] exactly as I had hoped using the following method.

The Gist

Soundtraxx Tsunami 2 decoders have an “alternate sound mixer” designed to make it easy to select a new set of alternate sound levels with the press of a function button. Additionally, the “function mapping” in Tsunami 2 decoders allows you to set any function to operate automatically when the command station commands the decoder in “forward driving,” “reverse driving,” “forward driving,” or “forward standing” conditions. The trick is to set all the alternate sound levels to match the primary sound levels EXCEPT the horn and bell which are set to volume “0,” then use the function map to configure the alternate mixer to operate any time the decoder is moving in the trailing direction (forward or reverse based on how it’s sitting in the consist), and finally to set up the decoder to “respond to consist address” for horn and bell functions. When you set up the locomotives on the ends of the consist in this manner, it has the effect of silencing the horns and bell when the locomotive is trailing and not leading. Here are the steps in JMRI.

 

 

 

 

 

Some of the settings will depend on where the locomotive is in the consist and whether or not its on the end. For a locomotive in the middle of the consist, you can either set the decoder’s light, horn and bell functions to “locomotive address only” in the consist tab, or you could place check marks in all four columns in the function map (forward driving, reverse driving, forward standing, reverse standing) so only the alternate mixer with zero volume for bells and horn are used. If you change the orientation of the locomotive, you may need to change the FL settings in the “consist” tab and swap from “forward” to “reverse” check marks in the function map. Also, if you’re using a locomotive on the end that doesn’t support an alternate mixer (like the Soundtraxx Econamis I have in some locomotives), then you’ll need to pick just one of the locomotives to “respond to consist address” to provide the horn and bell for the whole consist and disable the directional checks in the function map.

That’s it! Now when you run a throttle using the advanced consisting address, the lights on the ends will be directional, AND only the horn and bell of the leading unit will respond to the throttle’s horn and bell functions no matter which direction you’re running. Click on the video at the top of the page to see this in action, and if you’ve got some even better tips and tricks for this, please leave them in a comment below!