Overview - Function Remapping
NOTE: This section only covers the remapping of LIGHT functions, not SOUND functions.
Function mapping of lighting outputs can be done via the programming of Configuration Variables or via Audio Assist on WOWSound decoders. Your decoder literature pamphlet, as well as the programming resources available on this site will show the CV's and values that correspond to the function outputs and function buttons.
In the NMRA Standards document S-9.2.1 (currently under revision), the DCC standard for packet transmission (that is, the communication over the rails), function buttons for lighting are separated out into three function groups. Functions 0-4 make up the first group within the packet, and Functions 7-12 are part of Group 2. Group 2 is further divided into Lower and Upper groups, with Function 5 though Function 8 making up Lower Group 2, and Function 9 through Function 12 making up Upper Group 2. Note that in this context, the word "Function" is being used to refer to button numbers used to control the decoder, not actual output from the decoder.
Function Remapping - TCS Non-sound Decoders; WOWSound Version 4 and Older
In TCS non-sound decoders, as well as WOWSound Version 4 hardware and older, if a function is going to be assigned to respond to a command in one of these groups, it needs to be configured in that corresponding CV. Below is a chart identifying the CV numbers and corresponding values used to map a lighting function to a button number.
|Group A (Button 0 through Button 6)||Group B (Button 7 through Button 12)|
|Use values for buttons from above to program CV numbers for function outputs below
A value of 0 removes control of that output from any button within the group.
Functions 0F & 0R cannot be remapped above Button 6 in decoders of the defined
types (above) which use this chart.
|CV||Output No.||Default||CV||Output No.||Default|
|123||Rule 17 Dimmer||32||158||Rule 17 Dimmer||0|
|124||Blink Ditch Lights||8||159||Blink Ditch Lights||0|
As you see on the chart, Functions 1 - 6 have TWO CV's EACH. The CV on the LEFT of the chart can be used to assign a button from 0 - 6 to that function. A value of ZERO in any of these CV's will disable the function from responding to any button from 0 - 6. Along the RIGHT of the chart are the secondary CV's which correspond to buttons 7-12. By default, these CV's are 0. By programming a value to these CV's, a button or buttons can be assigned to activate the function from 7-12. Note that it is possible to have multiple buttons control the same function using this method if desired. It is suggested that only one CV for each function be programmed with a non-0 value to prevent de-synchronization or confusion.
Along the TOP of the chart are two sections with values from 1 to 128. The numbers from 0 to 12 listed above the values state what value would correspond to that button number. By programming the value listed below a button number, that button will be assigned the function whose CV was just programmed.
It is important to know the difference between a FUNCTION and a BUTTON.
- A FUNCTION corresponds to a numbered function output and/or colored wire from the decoder. For details on which color of wire corresponds to a numbered function output, refer to the chart above, or the NMRA Wires and Connector Standards.
- A BUTTON is located on your throttle or control device and does not necessarily directly correspond to any output from the decoder, as this can be configured.
Example: You are attempting to move a function to the higher function group. F2 -> Button 8. To do this, once again look at the chart. Function 2 has two CV's - CV36 and CV38. Button 8 is part of the higher functions, which would make use of CV38. Therefore, by selecting the value that corresponds to Button 8 (a value of 8), and programming that value into CV 38, Function 2 will now respond to Button 8. To finish the transfer, we need to clear the button from responding to Button 2. To do this, program CV 36 with 0. Now you are finished!