Titan advanced function mapping

Note: page numbers quoted are from the latest QSI manual, version 5.2.0

So, in several documents, the Titan is supposed to support function buttons higher than the NMRA standard mapping of F0 through F12.

But the only documented mapping tool is the NMRA mapping table, CV33 through 46. (page 66)

NMRA Function key mapping

The NMRA mapping allows mapping QSI "features" to a function key for F0 through F12. This table also allows mapping more than one item to a Function Key. Usually you can map up to 8 different items to that Function Key. This allowed a person to map for example the horn and ditch lights to a function key.

These are CVs 33 through 46 (page 66)

A reasonable idea when you basically had only maybe 6 outputs on the decoder.

When sound came around, manufacturers extended the use of the table to include sounds as well as the physical "function outputs" on the decoder.

Since you can (usually) map up to 8 "things" to a Function Key, that suffices for many situations.

Titan extensions to function key mapping & more

• A list of standard function key mapping is on pages 21 through 34. Note that different things may happen if the loco is stationary or moving
• The standard NMRA mapping for 14 functions (0-12) is NOT supported in Q2 firmware after June 1, 2008 (CVs 33 & 34)
• QSI added another structure for function key mapping, using CV53
• CV53 also "respects" the states of fwd/reverse (secondary index 0) and neutral (secondary index 1)
• Therefore you map a FEATURE to a FUNCTION KEY through CV53, but there are some exceptions:
  • some features cannot be programmed in neutral or moving on functions 1-14
  • don't assign the same FEATURE to more than one OUTPUT (OUTPUT defined later in this page)
  • really old firmware only works on functions 1-14, and only supports OUTPUTS 1-14
  • firmware that support F13-28 also supports OUTPUTS 15-30 (read bottom of page 119)

Note well, that lighting can be specified as in a group, called Multiple Automatic Lights. There are 3 such groups.

You can specify what lighting outputs (up to 12 lighting output ports, shown on the board pinout as LED1 through LED12) are in what lighting groups.

So:

• You can group lights into one of 3 groups
• Then map features to what QSI calls Outputs which are NOT the same as the physical LED outputs on the decoder

"Hidden" QSI Function Key mapping

So by interrogating the QSI Output mapping CV53.PI.SI I found that indeed you could change the SINGLE feature assigned to function keys 13 and up

Note CV53 has 2 settings, one for when it is in FWD or REV, and the other for Neutral (NFF and NFR)

The Outputs run from 1 to 30, so I started by looking at Output 30, and indeed found it was mapped to "Water Load" for F28 (only in neutral)

Continuing to investigate, it seems that Output X gets mapped to Function X-2

(below data is from my GP60 project)

from my testing, it appears that FKEY 28 is mapped to output 30

Titan FEATURE numbers

• Note FEATURE numbers are NOT the same as the Individual Sound Identifiers (page 118). The latter are used for setting individual volumes.
• FEATURE numbers can be tied to FUNCTION keys
• main feature list is pages 121-125
• some more "sprinkled" through other QSI documents, often the user guide packaged with the decoder.
• Below is a list of the FEATURE numbers I have found:

.