Dcc and CV 3 & 4

[Vizzin72]

Could someone please explain what CV's 3 and 4 do ? As I understand cv's 2,6&5 set start mid and max voltage respectively .... Cv 29 allows said parameters to be divided in to 28 steps .... How does cv 3 and cv 4 fit in to all of this?

Thanks

[bapguy]

CV3 is acceleration, CV4 is deceleration. CV2 is start voltage. CV2 affects at what speed step the loco starts to move. CV3 is how long it takes the loco to get up to speed. IE: if you turn the speed nob to speed step 20 and CV3 is zero, the loco will accelerate rather fast. Adding a higher value will cause the loco to accelerate at a slower pace. The higher  the value, the longer it takes to get to speed. CV4 is the opposite: how long it takes a loco to slow down when the nob is turned to zero. This is a simple explanation as people use the speed nob differently. Some turn it slowly to get the loco moving, others crank it up fast.    Joe 

[Vizzin72]

Ok so I have high value for cv3 causes it to get to speed slower,but a lower value causes it to get to speed faster what about cv 4 would a high value cause it to stop quickly or would a low value cause it to stop quickly

[Vizzin72]

Just to clarify .... I want to have the train start gradually in case my son gets to crazy with the control it doesn't abruptly take off at full speed and I conversely want it to stop real quick in case he is late slowing it down so as to prevent from crashes

[bapguy]

Set CV3 to around 30 or so. This will cause the loco to get up to speed slowly. CV4 should  be 0 as this will cause the loco to stop almost instantly when the throttle is turn to 0. If the decoder has cv5 and cv6, set cv6 to 40 and cv5 to 70. This will limit the top speed of the loco. Even if the throttle is full speed, the loco will be moving at a reasonable speed. Experiment with the CV5 and CV6 settings to adjust the top and middle speed. I have a small switching layout and set my locos to run around 35 scale MPH at full throttle.  Joe

[Vizzin72]

Thank you for the steps ... Yes I believe it has 5 and 6