Programming Dixtrax

[NILE]

I have some old Athearns that I am upgrading to DCC.  I find they are some what slower than other engines and have a really slow delay on the throttle.  What are some ways I can program these engines to have better performance?  I already update CV2 to increase the start voltage so that the engine we move on throttle setting 1 or 2.

[wjstix]

I'm not sure what exactly you're asking about - are the engines running slower at say 50% throttle than your other engines, or do you mean the engines seem to take a long time to react to changes in throttle settings...or both??

For the first problem, you could try adjusting CV 5 and 6 to higher numbers. CV 5 is top speed and CV 6 is midrange; normally I set the midrange to be about half of the top speed.

For the latter problem, you might have CV 3 and 4 - starting and stopping momentum - set too high. The higher those CV's settings are, the longer it will take for the decoder to move from one speed step to the next. Decreasing those numbers should make the engine respond quicker to throttle changes.

[rrinker]

 If there is a delay in the throttle action, perhaps you have inadvertantly programmed in some momentum. This is CV3 for acceleration and CV4 for deceleration. If you have non-zero values here, it will take a measured amount of tiem to move from one speed step to another no matter how fast you crank the throttle knob. The formula Digitrax uses is in their decoder manual, I think it's 10ths of a second or somethign liek that, off the top of my head. That means a value of 10 would make it take 1 second per speed step - so going from 1 to 60, about half throttle, would take a minute. CV4 does the same thing, but only when closing the throttle - if set to around 10 it would take 1 minute to go from speed step 60 to 0.

 Unfortunately, due to the order features were added to the NMRA standard, the CVs for start voltage, mid voltage, adn max voltage are not in order. CV2 is start voltage, CV5 is max voltage, and CV6 is mid voltage. CV3 and CV4 are in between with the accel and decel values.

                       --Randy