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Programming Soundtraxx OEM Locos Like Your Home Grown

Thanks Bob C. for making things easier!

Recently a friend of mine, who has a number of Soundtraxx steam Tsunami decoders installed on his locos acquired a Bachmann 4-4-0 with DCC sound (Soundtraxx OEM decoder). He called me frustrated that the function keys and some of the control functions differed from the Tsunami decoders he had installed in his locos.

I knew that there was remapping and reprogramming involved, and checked it out with Jarred Ireland at Soundtraxx to find out exactly what had to be done. I performed the steps covered in the attachment and successfully reprogrammed the OEM Tsunami to have the same function key outputs, and control functions as the aftermarket decoder we are all used to.

I thought it would make a good Tips and Techniques article, as I am sure many DCC users who have previously installed Tsunamis and have acquired Bachmann or Athearn locomotives with the OEM Tsunamis, have felt the same frustration as my buddy.

Function Key and Control Consistency between Aftermarket and OEM Soundtraxx Tsunamis

Currently both Bachmann and Athearn are buying Tsunami Decoders from Soundtraxx to be installed in their locomotives during the manufacturing process. Their market is analog (DC) model railroaders as well as DCC users. This has led both Bachmann and Athearn to map function keys differently from user installed Tsunamis. In addition they have activated analog operation controls to enable and provide sound functions, such as whistle on/off, grade crossing, braking and brake squeal, etc., based on increasing or decreasing voltage as controlled by the analog throttles.

These differences work well for DC users, and for DCC users who are just acquiring locomotives with factory installed Tsunamis, and have no interest in installing their own decoders. The inconsistency arises for those of us who have DCC and a number of locomotives with user (after market) installed Tsunamis. When the function keys on the differently sourced Tsunami decoders activate different sound controls, and when CVs are set differently, it is confusing and frustrating.

The solution is to program the OEM decoder with both function key mapping and CVs to have the OEM decoders work exactly like the ones we already have installed. The following steps will accomplish this.

Step 1. Reset the OEM decoder back to factory defaults.

Set the locomotive address back to primary (short) address. Program the decoder back to factory default to reverse any changes you may have made by programming CV 30 = 2. Turn the power off and then back on. Realize that the factory default is Bachmann’s or Athearn’s factory defaults.

Step 2. Remap Function Keys

Change CV 30 back to value of 0 (Bachmann’s default for CV 30 is 4 (Function Key Swap activated).

Change CVs 33 – 46 to remap the function keys back to the after market settings as shown in the Tsunami users guides (steam and diesel), and the corresponding reference manuals.

The Soundtraxx default settings for Function Outputs are as follows:

F Key Function(s) activated CV # CV Value
FO (f) Headlight/Dynamo 33 65
FO (r) Backlight/Dynamo 34 66
F1 Bell 35 8
F2 Whistle/Horn 36 4
F3 Short Whistle (toot) 37 16
F4 Steam Release 38 32
F5 Function 5 Output 39 2
F6 Function 6 Output 40 4
F7 Dimmer 41 16
F8 Mute 42 32
F9 Water Stop 43 8
F10 Injectors 44 32
F11 Braking 45 64
F12 Coupler 46 128

Function Key Swap

At this point, if you wish, you can reactivate the Function Key Swap (F5 - F8 for F9 - F12) by programming CV 30 = 4.

Analog (DC) Operation

Make the appropriate CV changes to Analog operation.

The Soundtraxx Defaults for analog operation are as follows:

Power Course Conversion CV 12 = 1
Miscellaneous config bits * CV 29 = 2
Analog Function Enable 1 CV 13 = 0
Analog Function Enable 2 CV 14 = 3
Analog Mode Auto Sound Config CV 197 = 0
Analog Whistle Control CV 47 = 0
Bell-On Set Point CV 193 = 15
Bell-Off Set Point CV 194 = 19
Grade Crossing Whistle Sensitivity CV 195 = 4
Brake Squeal Sensitivity CV 196 = 3

* (Note: to determine appropriate setting look at Table A Quick Reference Table for CV 29 Values), which can be found in the Soundtraxx users manuals).

At this point you have restored the OEM decoders to the equivalent of the aftermarket Tsunami decoder, making the function keys and controls the same as the ones you are used to .

Please note that if for some reason you have to reset the OEM decoders back to factory default they will be reset to Bachmann’s or Athearn’s predetermined factory default settings. The loco manufacturers’ default settings are “burned” into the decoder and cannot be changed. You will have to repeat the above steps.


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