RailComPlus & M4 Master Decoder Synchronisation

Perhaps you know the problem: You have equipped a locomotive set with two (or more) LokSound 5 decoders: one decoder for each power unit. All decoders were correctly configured and installed. The locomotive set is now to be operated with your ESU ECoS, ESU CabControl, or Märklin Central Station. The problem: All decoders will automatically create themselves in your control center with either RailComPlus or mfx and receive a different address. Until now, it was not possible to give both decoders the same address in either the mfx or the RailComPlus system. The only remedy so far was to include all locomotive decoders in a consist and control them together. The alternative of switching off RailComPlus or mfx / M4 in the decoder and manually creating the decoders with a (common) DCC address is also not convenient.

With the new LokSound 5 firmware from version 5.1.101, ESU takes care of this problem and is once again the first decoder manufacturer to present a solution to the problem. With the automatic master decoder synchronization, the address of second, third, fourth, etc. decoders in a locomotive or railcar set must always be compared with the automatically assigned address of a "master decoder". This is done fully automatically without manual intervention. For this to work, all slave decoders must know the serial number of the master decoder. Follow these steps:

First, the serial number of the master decoder must be determined.

  • Connect the master decoder to the LokProgrammer. Make sure that only the master decoder is programmed. If necessary, temporarily disconnect all slave decoders.
  • In the LokProgrammer, switch to the function "Read CVs", then "Decoder Settings" and then press "Read Decoder Settings"
  • Make a note of the serial number of the master decoder.

The next step is to configure the slave decoder:

  • Connect the slave decoder to the LokProgrammer. Make sure that only the slave decoder is programmed. If necessary, temporarily disconnect all other decoders.
  • Read the slave decoder completely into the LokProgrammer.
  • Switch to "Decoder", then "Special Options"
  • Activate the RailComPlus and M4 Master Decoder synchronization.
  • Enter the value 151 for ESU for the manufacturer ID and the value you determined earlier for the serial number.

You can now finalize the entire locomotive or railcar set electrically and place it on your layout. As long as the synchronization function is active, the slave decoder will now always have the same RailComPlus address or M4 address as the master decoder. Even if you change the locomotive at the ECoS, CabControl, or Central Station, this will be carried over.

However, keep in mind that the slave decoder can no longer be read out via RailCom on the main track in this mode. Since it has the same address as the master decoder, two decoders would respond, which would lead to chaos and errors. Therefore, the slave decoder does not respond to RailCom "read" requests. RailCom "write" requests on the main continue to be accepted by the decoder. All locomotives in the set will be programmed with the same values, otherwise remove those that you don't want to have the same values during programming.