# Problems with SoundTraxx CV61



## SSBN743 (Dec 30, 2013)

Hey everyone; I was hoping I could get some help with Soundtraxx (Tsunami) decoders, specifically, the braking function, acceleration, and deceleration functions.

After many hours of reading and trial and error, I believe I understand that CV3 is for acceleration, CV4 is for deceleration, and CV 61 is a braking function. Now, as I understand things, CV’s 3 & 4 are used internally while CV 61 is actuated by the F11 function by default – it also plays the brake sound in addition to actually applying the brake, according to everything I have read anyway.

So, I have CV’s 3 & 4 working fine with no issues to speak of; CV 61 on the other hand is a different story. On the Soundtraxx website, there is a page that advises setting CV’s 3, 4, & 61 to 25, 75, & 178 respectively as a starting point, however, when I place any value in CV 61, the Loco will not move at all.

The manual defines CV 61 as needing a value between 0-255 with bit 7 controlling polarity. So, values 127 or less provide a positive value added to CV4, and values 129 and higher (0 & 128 disable) provide a negative value to CV4 – and only when the function is activated – which brings up the obvious question; why does my loco refuse to move with a value in CV61 even though the function is not being activated?

I have tried many values all over the spectrum, both positive and negative and all of them have the same effect; the loco starts up and the RPM’s start increasing to max but does not move; I have tried 1, 64, 127, 129, 192, & 255. The only way I can get the loco to move is to set CV 61 to 0 or 128.

Does anyone have any ideas here? What am I missing?


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## SSBN743 (Dec 30, 2013)

Ok, sorry guys – through shear luck, I just answered my own question.

Apparently, setting a brake value in CV 61 enables the brake when the loco is stopped. Applying forward direction and throttle does nothing, until you release the brake by using F11. Then the loco starts moving, accelerates correctly, decelerates correctly, and a re-applies the brake when F11 is pressed.

So, I figured it out, but there isn’t even a hint of this in any manual I have found; FYI!


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