What voltage are you changing? Are you talking about changing CV2?
Ethan,
Are you doing this in programming track mode or programming on the main (POM)? Since I'm assuming you are adjusting CV2 (Vstart), do you know what the default value is?
If you aren't already, Ethan, use your programming track to read back the default value of CV2 for that particular NCE decoder. You then should use that value as your base and adjust Vstart up and down from there.
Tom
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The Menu's on the Power Cab don't work on all decoders. The menu asks for minimum mid and max values. Some decoders only accept 1 value (Start) some 2 values.
If you know the decoder in the loco you should be able to quickly look the informatoin up and program the individual CV's.
Jim
Springfield PA
Ethan.
You stated that after resetting the decoders they work normally. This leads me to think that there is nothing wrong with the power cab itself. What I am inclined to think is that you need a better understanding of how DCC works in relation to the motor control. With DCC there is a constant voltage on the rails all the time. The decoder in the locomotive is the regulating item that controls how much voltage and current actually gets to the motor. The decoder uses CONTROL VARIABLES (CV) to regulate the power to the motor. There are 5 basic motor CVs that control how the motor will act. CV2 is the starting voltage. Adjusting this CV will get the motor turning. It should be set as low as possible to get the loco moving. CV5 is the top speed of the motor. If it runs too fast then turn this down. You can never make it run faster. CV6 is the mid range setting. This should be in the middle of CV2 and 5. CV3 and 4 are used to add and subtract momentum of the spinning motor.
There are many links to the basic understanding of how this all works. I suggest you read up on programing decoders before changing them.
Pete
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Been Nothing Since Frisco (BNSF)I don't use CV's, I go to program on the main: hit 4 and it goes through all that with out having to punch in separate CV's. It's always worked for me, till now. And it's not just 1 type of decoder that's being effected. In all the engines I have D13, D14's, and a D15.
Hey Guy.
Hmmm, I have had my Power Cab for about 4 years and have never had it do that for me, but I have never had a problem setting CVs. It might be a good idea to re-read how to set speeds.
Lots of good luck.
Lee
It sounds to me like you're setting the Momentum in the Power Cab, which does not change anything in the decoders, and does not have any effect on speed steps or speed matching..
Okay, here's what I did with my power cab.
I removed all loco's from my layout and when to program on the main. I type in a loco address and hit 4 like the OP said he did. My power cab asked for values for (in order): start volts (CV2), max volts (CV5), mid volts (CV6), acceleration (CV3), deceleration (CV4), PWM frequency (I'm not sure what CV this programs), kick rate (CV 116 on NCE decoders), and kick depth (CV 117 on NCE decoders).
It seems that pushing 4 on POM mode opens a shortcut for motor setup. POM does not read CV's so you can't tell what the default values are using this method, which means you should definitely study the decoder manual before punching in values.
I'm not an expert on this either, I've only had my power cab for a few months. It would appear that one of the CV's I listed above could be the cause of the problem though.
Good luck,
Jamie
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RailfanS It seems that pushing 4 on POM mode opens a shortcut for motor setup. POM does not read CV's so you can't tell what the default values are using this method, which means you should definitely study the decoder manual before punching in values.
Thanks, Jamie. I didn't even know there was a short cut to that.
Again, Ethan, that's why knowing the default of CV2 (Vstart) is important because you then know where your starting point is before changing values. It's also wise to only change one CV at a time to see how it affects your locomotive. (Speed steps would be the one exception to that rule.) When you start changing two or more CVs simultaneously, you don't know which one made your locomotive start acting up.