DCC

[Anonymous]

I just installed a Digitrax Decoder DH123D, and everything seems to be working ok except for the speed control. The forms that come with the decoder state that the factory default is set at 128 speed steps. I have the Digitrax Zephyer and the engine does not start to move until the throttle is on nuymber three. Then full speed is far less than it is on DC Even when running the analog engines on 00, they do not obtain full speed either.
Is there some way to adjust the speed control?

Bob

[Anonymous]

You should have a Digitrax decoder manual. It shows you how to program in whatever speed curve you want with the CVs. It may have some default speed curve in it that gives the results you see. Another thing you might check is just what the voltage is on the DCC track. Your DCC system may be limiting the voltage so that you get less with DCC than you get with DC. My club usually runs about 16 volts because of the layout size and the voltage drops that go with it. These things are adjustable but you have to read the book. And Digitrax books are not easy to read unless you're an electronics engineer.

[Modeloldtimer]

The first Cv to program is Cv01 (AD2) and or Cv17;18. Cv01 is fractory set to a value of 03 on new decoders.
Cv01 is the decoders primary address. While Cv17;Cv18 is it's extended address.

To set the primary address just set Cv01 (AD2) to the desired address between 1 and 127 digital or Hex. Use service mode to set the primary address.
Check Manual for other programing modes which can be used.

Now program Cv29 for the desired operating mode to control lights etc.
To use primary address, speed table 28/128 and locomotive direction set to normal set Cv29 to a value of 06 of which it's default value and is already set from the factory .

SET THE START VOLTAGE for your Locomotive.
To set Cv2 which is the start voltage. Using ops mode programing . Turn your throttle to the first speed step and then increase the value in Cv2 until the locomotive just begins to move. You can also program Cv3 and Cv4, they set the trains accelerating and braking momentum do to the train weight. Just set to a value greater than 0. Turns it on.
Suggest a value of 14 to 20 to start. The higher the Cv4 value the longer will be the trains stoping momentum. The higher the Cv3 value the longer will be the trains starting momentum.

Here's a link to the Digitrax Decoder Programmer Manual.
http://www.digitrax.com/ftp/Decoder%20Manual.pdf

I love DCC

[Anonymous]

Help has arrived. I first checked all the circuits and wireing for a short, and did not find one. I then took a section of track and laid it on the floor and conected the Zephyer to it. The engines had the same problems. I then called Digitrax and talked to them about it. They told me that they had never seen a problem like I am having. He had me do a couple of resets of switches that did not help. I told him that the analog engine only ran in one direction at normal speed and the other engines with the decoders ran in both directions at slow speed. He was completely puzzled. I had to ship the box back to him for they can see what went on. Turnaround time is 2 weeks as they are short handed.
Thanks for all your suggestions, and GOOOOOOOOOOOOOOOOooooooooooooooooo
GATORS !!

Bob

[dave9999]

Bob,
I read this after I posted on you other topic, so ignore my question about Digitrax's response. Locomotives run slower under DCC power. This was the first thing I noticed
when I switched. My MRC DC pack put out 18v DC, so a steam loco looked like a bullet train when I opened up the throttle. But the control is worth the sacrifice in top speed.

Fellow Gator Fan, Dave

[electromotive]

Try this:
The DH123 (series 3) decoder has a lot of new features and therefore acts a
little different.
In order to have this decoder perform like the older versions, you must
disable some of the features that are ON by default.
First, set CV9 to xFF or 255 in decimal.
next, set CV54 and 57 to x00 or 000

You can also achieve further adjustments by changing the start, mid and max
voltage on that decoder