Function key protocol

[Tim Brien]

Is there a set of rules relating to what function (F1 - F16?) is attributed to each of the keys on the keypad of the cab control?

 

[ntpntpntp]

No hard-and-fast rules, although I expect the NMRA have made some recommendations.

 

[don9GLC]

I don't think the NMRA specify this.
According to RP 9-2-2 these are customizable by the user.

Not the clearest explanation I have ever read!

 

[whatlep]

I don't think the NMRA specify this.
According to RP 9-2-2 these are customizable by the user.
Not the clearest explanation I have ever read!

Chaps

Beware of confusing the variables asked for by (for example) the Massoth manual which are entered in conventional (decimal/ base 10) numbers and the NMRA data which is using computer-speak (binary/hexadecimal notation) as its basis. The table previously quoted is referencing binary which is not what the user needs to enter a CV value.

The short answer to Tim's original question is no, there is no stated protocol. Massoth (and I guess other European suppliers) supply DCC decoders which default to the obvious logic of F1 = key 1, F2 = key 2 and so on as far as F6. Above that life gets complicated. For example F8 defaults on Massoth chips to entering/leaving "shunting mode". Functions above F6 are esoteric to each chip manufacturer and - as I understand it - primarily driven by the North American market's requirements for esoterica such as ditch lighting and dimmed headlights for train meets. My apologies if that last sentence is incorrect, by the way.

May I recommend to Tim that if in any doubt, he resets everything to factory defaults (using CV 7 programmed successively to 55,66 and 77) and then slowly and carefully starts over, possibly with those pesky lights (CV53 for both front and rear - my chosen value is 5).

 

[Tim Brien]

Many thanks for help. For info I did have '5' set at CV 53. While I understand the reasoning behind the light dimming , I could not understand the CV side of it. What is needed is a "DCC for Dummies" book.

 

[mbendebba]

Someone please correct me if I am wrong, but CV53 does not control voltage to the lights in a direct decoder interface install situation, CV50 does. CV53 controls voltage to whatever is connected to A1, A2, or both.

 

[Tim Brien]

Mohammed,
the LGB MTS reads CV 53 as rear light. Massoth reads CV 53 as the dimming voltage of A1 and A2 and CV 52 as rear light.