Address 0 as a Broadcast with Digitrax Hardware

Recently, at the Hostler’s Model Railroad Museum in Ogden, Utah a museum member brought several locomotives to run on the museum layout. The one locomotive he really wanted to run, however, would not. After several questions by the author it became apparent that the engine’s address was not quite what the member thought it was. With no programming track available to program CVs plus Programming on the Main (POM) requiring the engine’s address be known, the member was not sure how to go about fixing the address problem.

The key to the solution in this case is the fact that Digitrax hardware utilizes address 0 which is defined in the NMRA standard S-9.2.1 as a broadcast address to all powered locomotives on the track the throttle is communicating with. If your hardware is different check the documentation for usage of address 0. Even though this is a standard not all hardware follows it.  

<CAUTION>The following procedure will modify ALL locomotives that are on powered  track when this procedure is performed. Therefore, remove any locomotives or move them to a section of track that can have power removed from it except for the engine you want to change.

Changing the Address

Long addresses (4 digits) are contained in CVs 17 and 18 according to the NMRA standard. Utilizing the phone app DCC Tools and selecting Long Address Calc enter the address in Long Address value. The values of CV 17 and 18 will be given below your entry (the phone app Digitrax Tool Box has been discontinued. You can read about that here).

Utilizing a Digitrax throttle select address 0 then select POM (how to do that depends on which throttle you have so we will not discuss that here). Write  the values given by the app into CVs 17 and 18.

The next step is to change CV 29 to use long addresses. Use the phone app’s CV29 Calc function to calculate the proper value and enter it into CV29.

Lastly, exit programing mode, select the entered address on the throttle and test the engine to see if you did everything correctly.

This procedure can be a life saver in certain circumstances but is virtually impossible to use if there are several other engineers running their trains on the same layout.

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