FAQ - How do I use RailMaster to write CVs on a decoder that is not recognised?

[Chrissaf]

This is a question that comes up with some regularity. Sometimes, the raised question is alternatively along the lines of 'I can't write to CV number XXX on my recognised decoder'. Both these questions can be resolved by following the process documented below.

The key to resolving these issues is to NOT use the RailMaster decoder database.

Place your loco on the 'Programming Track'.

Open the RailMaster 'Locomotive Settings' screen.

Do NOT select your loco from the 'Loco Name' list in the upper left portion of the screen.

Instead, scroll down to the bottom of the 'Locomotive Settings' screen and click the " i " icon.

The following screen will open.

Now this is the important bit. Do NOT try to read any CV values using the Green tick.

If these instructions above are followed, then this screen becomes a generic CV writing screen for any DCC decoder regardless of brand and model [see note below].

You can now use this screen to write a value to any of the CVs supported by the decoder. Use your decoder documentation to identify which CVs have which function and their valid data entry range.

The reason for not using the 'Read' function, is that any attempt to read a CV will force RailMaster to look for the detected decoder in the inbuilt database and this can prevent certain CVs being 'written to' if an incorrect decoder is inadvertently selected from the database.

Note: You can even use this screen in this mode of operation to write the CV of a Hornby R8247 Accessory Decoder [needs to be connected to the 'Prog' controller output]. This then allows the R8247 to be 'Factory Reset' by writing 8 to CV8. This is something you cannot currently do with the RailMaster 'Standard Edition' using the R8247 Accessory Decoder configuration screen.

Also Note: Short DCC Addresses [001 to 127] can be entered directly into CV1 labelled as 'Primary Address' in the image above. Long DCC Addresses [128 to 9999] are stored in multiple CVs [CV17, CV18 & CV29]. It has been found that trying to write a long DCC address manually to these three CVs is a bit hit and miss. This RailMaster CV writing screen gives a utility tool for writing long DCC Addresses to the decoder more simply. Use the 'Sigma' icon [image below] and follow the on-screen prompts.