FUNCTION MAPPING.

[shibushe]

Would someone explain to me what exactly is Function Mapping. 

And why would one need to do it.  Thanks.

[Nigelcliffe]

Function mapping is deciding which outputs (lighting wires, behaviours (eg. half speed, shunt mode), and sometimes sounds )  are controlled by which Function Keys.   The settings reside in the decoder, and are set by programming.

 

 

Why you might want to change things is down to you,  could be wanting certain features on certain keys,  might be wanting to use (or avoid) a particular function key on the handset,  might want to hide away a feature you rarely use, thus freeing up some keys for other tasks. 

 

 

 

There are some default recommendations from the NMRA standards, which make the front and rear lights operate from the F0 key  (Note that F0 Key in Forwards direction is technically a different function to F0 Key in Reverse direction).

The NMRA recommendations are very limited in what can be done, so many more advanced decoders offer options outside the NMRA arrangements.  
Some of the advanced decoders are now sufficiently complex that changing the function mapping on just a DCC handset is difficult, a computer interface makes things much simpler. 

 

 

 

- Nigel

[Maxwill]

A fancy way of saying "changing which function button does what"  For instance, if a button on your controller is set to make a sound or turn something on/off like lights, then you can set it to any button of your choice. Make sure you save a map of the functions first, either on paper or other means.

[ColinK]

A reason for doing it is to standardise what the buttons do for each loco. For example, I have sound decoders from several different suppliers. Many of them have sounds like 'sleeper groan', but on different f buttons. So by revising the function mapping you can standardise on eg F9 for sleeper groan, f8 for guards whistle, f7 for cab door etc.

 

I would love to remap all my locos, but I'm not sufficiently expert to do it.

[Maxwill]

http://www.dccconcepts.com/PDF_Downloads/DCCdecoder_instructions.pdf

 

Read this for a start, it is worth it.

[ColinK]

Thanks for that link Maxwill. I found it very interesting. It does raise another question, so rather than divert the thread, I'll start a new one.

[Crosland]

http://www.dccconcepts.com/PDF_Downloads/DCCdecoder_instructions.pdf

 

Read this for a start, it is worth it.

 

Don't blindly assume it will apply to other makes.

 

Andrew

[Oldddudders]

Would someone explain to me what exactly is Function Mapping. 

And why would one need to do it.  Thanks.

Mismatches between decoder and throttle do occur. I have a Digitrax system, which suits me fine with my mainly-US HO models, but when I use a European decoder there can be problems. In the US, F2 controls the whistle or horn, so is by definition non-latching. I press it and then release to stop the sound. On some European models, F2 controls lights, for example, for which a latching function is obviously essential. Cue a function re-map. I'm not really bright enough for these - but Nigel Cliffe (see post #2) has helped enormously.

[shibushe]

Many thanks for all the info guys. Me thinks I will leave things as they are.

[AMJ]

I used a remap for one half of the blue Pullman. With the factory defaults the cab lights at both ends were on the same function mine has it so each has a different F number. Drivers can turn on the cab lights independently.