So I have a locomotive that has both a sound only and motive only decoder...now what?!?!
Step 1 - take a deep breath...
Step 2 - exhale slowly...
Step 3 - read on.
Step 2 - exhale slowly...
Step 3 - read on.
It's not as big a deal as you may think. The time honored method is to use the long and short addresses to separate them out for programming. Really?!?!... How?
First, you have to realize that it will be necessary to unplug/unsolder one of the decoders while you configure the addresses of the other one. That way you are guaranteed to not inadvertently program both with the same values (except for the long address...read on).
Second, set the short addresses of each decoder to be different and the long addresses to be the same. Many use the 4-digit cab number for the long address in both decoders, then use the first 2 digits for the short address for the sound decoder and the second 2 digits for the short address of the motive decoder. If your locomotive only has 2 digits then you are on your own (sorry).
First, you have to realize that it will be necessary to unplug/unsolder one of the decoders while you configure the addresses of the other one. That way you are guaranteed to not inadvertently program both with the same values (except for the long address...read on).
Second, set the short addresses of each decoder to be different and the long addresses to be the same. Many use the 4-digit cab number for the long address in both decoders, then use the first 2 digits for the short address for the sound decoder and the second 2 digits for the short address of the motive decoder. If your locomotive only has 2 digits then you are on your own (sorry).
So with decoder 2 unplugged set decoder 1's CV29 to use 2-digit addressing by setting bit 5 to 0 and set the locomotive's short address to the first 2 digits of the cab number. Then set CV29 bit 5 to 1 and set the locomotive's long address to the cab number.
Now, after plugging decoder 2 in and unplugging decoder 1, set decoder 2's CV29 to use 2-digit addressing by setting bit 5 to 0 and set the locomotive's short address to the second 2 digits of the cab number. Then set CV29 bit 5 to 1 and set the locomotive's long address to the cab number.
Here's an example. With a locomotive cab address of 5291, decoder 1 responds to address 52, decoder 2 responds to address 91 and both decoders respond to address 5291. (Don't forget to plug decoder 2 back in)
Now, after plugging decoder 2 in and unplugging decoder 1, set decoder 2's CV29 to use 2-digit addressing by setting bit 5 to 0 and set the locomotive's short address to the second 2 digits of the cab number. Then set CV29 bit 5 to 1 and set the locomotive's long address to the cab number.
Here's an example. With a locomotive cab address of 5291, decoder 1 responds to address 52, decoder 2 responds to address 91 and both decoders respond to address 5291. (Don't forget to plug decoder 2 back in)
One caveat with this method. If the sound only decoder is a Digitrax SoundBug you can't use JMRI to assist with this method. This is due to the SoundBug's inability to provide an acknowledge signal after a change. JMRI must have that acknowledge signal to recognize the decoder.
This is just one method. If you know of another please leave a comment with a short description of how to do it.
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