Diesel Version 5:CV 138

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CV 138
Throttle Mode Selection
Range of Values0-2
Accepted Values0-2
Default ValueVaries

NMRA CV 138 - Throttle Mode Selection

There are 3 different throttle modes in the WOWSound decoder to choose from, TCS offers Traditional Throttle Mode (slot car mode), Prototype Mode, and Manual Notching. Each mode offers different levels of control and prototype authenticity. The WOWDiesel decoder defaults to Prototype Throttle mode which gives the most prototypical performance by taking advantage of TCS's revolutionary Proto-Notch™ technology.

The easy way to select a throttle mode is to use menu 4.1 of Audio Assist™.
Additionally this CV can be manually programmed by entering the value of the desired throttle mode into CV147

Throttle Mode Value
Traditional Throttle mode 0
Prototype Throttle Mode 1
Manual Notching Mode 2

Traditional Throttle Mode

Traditional throttle mode is how sound decoders of the past would "traditionally" operate, where the prime mover notch is related directly to the speed, every (n) speed steps (of 128 speed steps) is a different notch, so the faster you go the higher the notch you will be in.
The speed setpoints that the prime mover changes notches are controlled by CV165 through CV172 where CV165 controls when the locomotive goes into Notch 1 and CV172 controls what speed step the locomotive goes into Notch 8 By default TCS WOWSound decoder operate in Prototype Mode.
Traditional throttle mode is also available though and can be selected using Audio Assist® menu 4.1 or by programming CV147 Throttle Type

Prototype Mode

TCS brought auto notching to the model train hobby with the advent of the very first WOWDiesel decoder. It is arguably the coolest feature of the WOWSound decoder!

Auto notching is only available in the Prototype Throttle Mode. Auto notching allows the decoder to sense the load it is under, and decide what notch to be in. Auto notching is unlike Traditional Throttle Mode where the active notch is based exclusively on the speed. With Auto notching the prime mover sound is constantly changing as it goes up hills, around curves, picks up more cars, and coasts down hills!

In order to make the best use of auto notching, you must calibrate the locomotive in Audio Assist® so it knows what the ruling grade is on your layout and will be in notch 8 as it traverses it. Every locomotive is different, both in the sense of unqiue characteristics of the motor and gearing, as well as the "normal" operating conditions in which you run it. All of these factors need to be accounted for, and thus a calibration is needed in order for the decoder to "learn" your railroad.


To calibrate your WOWDiesel locomotive so that it knows the ruling grade and downhill grades on your layout enter Audio Assist™ and go to the calibration menu (menu 3.2) and follow the audio prompt from the decoder. It will ask you to run the locomotive in a coasting condition and then a notch 8 condition. (PRO TIP: While on the calibration menu you can calibrate the coasting point by pressing function 1 or the notch 8 point by pressing button 2, even if the menu is telling you to do otherwise)
Behind the scenes Audio Assist™ is saving the calibration data to CV152 BEMF Calibration Low and CV154 BEMF Calibration High both CV's can be programmed tweaked manually. TCS recommends calibrating using Audio Assist and then manually tweaking the CV's if need be.

Manual Notching

Diesel Version 5:Manual Notching