work in progress by hermannk - not ready yet !!!
Foreword 0: as described in the wiki, the settings are only saved if the "Description" field contains an entry!!!
see https://wiki.rocrail.net/doku.php?id=loc-fun-en

Foreword 1: the function zero (function "F0") has a special role. It is intended for the "light" function and there is therefore no way to redirect function number zero to another function number (mapping).

Foreword 2: if the handheld controller enables easy-to-read function labels, mapping should avoided, but rather display the full range of functions of each locomotive individually on the handheld controller.

Using a handheld controller to control the locomotive and the locomotive functions, there is often no space on its buttons for extensive labeling and certainly no possibility for variable labeling. Somehow we have to deal with the function numbers from 1 to 32.

The following function number assignment could exist for three locomotives:

One possibility is to define yourself one function number list that should apply to all locomotives.

In this example, the function numbers are to be used as follows:

The following requirements are made in this description:

With the function numbers-mapping for each locomotive, the fixed handheld function numbers can be translated into locomotive-dependent function numbers. The following cases can occur:

Prerequisite is however: function number 32 does not occur in our locomotive!

In the properties of our locomotive, at first create the fixed handheld controller function number list (e.g. by "copying" an already well-established locomotive). Then enter the manufacturer function number of our locomotive in the fx column. The reserved function number 32 is entered for all functions that do not occur.
In this example, the range of functions of the handheld controller is defined as follows:
- handheld function numbers 1 to 9 are reserved for the locomotives;
- handheld function numbers 10 to 19 are reserved for trains / car s;
- handheld function numbers 20 to 31 can be used individually;
- the handheld controller function number 32 is reserved as "unused".

Special feature: Rocrail processing time is saved if a zero is used in the mapping for the same function numbers for handheld and locomotive: fx = 0
Example: handheld control # = 3 "whistle" and our locomotive fx = 0 "horn 1"

In this example, button 9 on the handheld controller should be the "shunting gear" for all locomotives;
- our new locomotive uses function no. 24 for the shunting gear;
- the mapping fx = 24 is then entered in the properties of our locomotive for function # = 9.

As for a locomotive, a function number list for a car can also be specified …

… and if necessary it can be incorporated into the function number list of a locomotive. (see "coupler car 1" to "coupler car 4" in the table above).

The functions of "Locomotive and Train" have now been defined on the handheld controller.

Basically, Rocrail passes on the function number of the handheld controller to the locomotive as well as to all cars in the train.

n each car there is then the option of redirecting the hand controller function number to a car function (mapping).

Example: hand controller # = 11 "Coupling car 1" is redirected to car function 5 by Fx = 5 for car 1 ("car151").

With this configuration the functions of the locomotive can be operated, the two cars can be uncoupled individually and the interior lighting can be switched on and off in all cars at the same time.

There are vehicles that have a separate function decoder with a separate address installed. To support this the definition for the function mapping may use an address in addition to the function number. see https://wiki.rocrail.net/doku.php?id=loc-fun-en#address_fx
An example for a separate function decoder address of a locomotive (without a train) can be found at **Test 6**.

The function definitions for a locomotive and two cars listed in this documentation should be checked for their validity in several tests. For this purpose, the train "op_51-en" was coupled to the locomotive "lc_11-en", which consists of the two cars "car151-en" and "car152-en". After clicking a function button on the handheld controller, the result was read out in Rocview's controller trace window and documented here.

Preliminary note 1: Addresses are used for an MBUS controller:

Preliminary note 2: "fn=32, val=1" means: function-nummer=32, value=1
Preliminary note 3: the tests were done with Rocrail version 2.1.755 with this workspace.

The locomotive should whistle and the two cars do nothing; the handheld controller function number is identical to the locomotive function number:

The locomotive is supposed to activate the "shunting gear" and the two cars do nothing; the hand controller function number is different with regard to the locomotive function number:

The locomotive doesn't do anything, but all cars should activate the "interior lighting":

The locomotive doesn't do anything, but car 2 should activate the coupler:

The locomotive doesn't do anything, but car 1 should activate the coupler:

The handheld controller does function F27
- for locomotive "lc_11plus-en" which has the address 113 = 0x4071 and
- the separate controller has the address 114 = 0x4072.
The locomotive doesn't do anything, but the separate function decoder should execute function number 26:
F27 Adresse="114"="0x4072" fx="26"