Hey Everyone
Im kinda new to programming CV’s. Im just start to program all my locos right now. Is there a website or a book, describing which CV’s are good certain loco type. I talked to some people they program the CV’s like the real life loco. Delayed start up and such. Can anyone help me?
There are no industry standards for CVs per se…it is best to see what decoder you are using, go to the website of the mfg of that decoder and print out the CVs…After that you adjust to your hearts delight.
David
Hmmm, a timely post from my perspective. I was at my LHS the other day, and he was playing with CV’s 3 and 4, the momentum values. I got home and gave it a try. It seems that the larger you make the number, the longer it takes for the engine to come up to speed and to slow down. I assume one is acceleration, and the other is deceleration? So far, I’ve been setting both to the same value. I put a value of 20 into some engines, and 5 in my switchers where I wanted a faster response to braking.
Next I guess I’ll try CV 2, start voltage. Any suggestions?
The manual for the decoder usually offers a default value that comes already programmed. Usually, that is sufficient. HOwever, they also give you the possible ranges for all user-programmable CVs. So, if the loco begins to move instantly and somewhat abruptly on speed step “1”, find out the programmed value in CV 2, and reduce it by 30%. Exit programming and try speed step “1” again. Keep doing this until the locomotive just barely gets underway on speed step “1”. Note that as the loco wears, it may require a smaller number, indicating less voltage required to get it moving. Maybe, maybe not…maybe it will actually have to be adjusted upward over time if parts get sticky.
Does that help, Mr. B?
It’s much broader than what you’re looking for, but Digitrax has the Big Book of DCC which comes in pretty handy.
CVs 2, 3 and 4 would be the main ones to control start, momentum, and acceleration. The rest just fine tune the speed tables and control lights and functions. You can change CV29 to get an engine to run backwards, as the normal direction, if you want to run two locos, back to back. I think a value of 7 in CV29 does it, but I might be wrong.
A bit, anyway. I’ve got a few that don’t start until I get in the 3-4 range. I suppose I should increase CV 2 for those? Or maybe I should Read The Fine Manual. Most of my engines have basic Digitrax 123’s or TC’s in them, and I’ve never tried individual tuning to really fit the engines.
Yes, exactly…try a slightly higher value for whatever CV2 is on this decoder. Usually, if your decoder is at, say, 35, you would only raise it to 37 and that should suffice to make speed step “1” the first step to get the loco underway…coupling speed. But, it’s a trial and error thing.
The other thing is, if this is an older QSI, its BEMF capability may have been permanently incacpacitated due to the court battle with MTH. So, it will never have the ability to really crawl. You can get it to move on speed step “1” eventually, but it will be somewhat faster. If it has a good BEMF, it should take nearly 1 minute to do a full revolution of the drivers.
For CV’s 3 and 4, you set them up so that your loco accelerates and decelerates as you’d like it to. Maybe you’d rather it stop quite quickly when you dial down the throttle setting urgently, so you could have no momentum in CV4. Alternately, maybe half of the inertia setting in CV3? Your choice. Personally, I like close-to typical settings, so my J1 is set about 70% of the maximum for both. My yard 0-6-0 and SW8 are about 1/4 of the max setting so that I have more control in tight situations.
Have fun!
Not to mention the need to spend extra funds to add on a chip to give the older BLIs back thier extra capabilities. I suppose it’s cheaper overall than getting a new engine, but I feel I should not have to upgrade because of a court battle.
My CV’s are based on the global reset if needed and addressing. Some of the engines have horns, bells disabled like the B units. Everything else is left as it is as the binary code availible in the manuals are just too risky for me. I probably will end up getting DecoderPro and programming off my computer instead of attempting to turn my engines into bricks because I entered a wrong CV.
I have several newer engines that respond to the Back EMF and crawl at speed step one and they represent the future. Something that should have been done long ago.
One other thing Ive noticed. I try to keep one manufactor for all of my DCC engines because having several different manufactors results in a library of books filled with CV values for each engine because the Manufactors refuse to use one CV for one thing all the way across the hobby. CV so and so might be the bell volume on one engine but not on another.
I generally set the acceleration and decelleration the same for earch type of locomotive. I.E. all Dash 8’s are set the same, all Dash 9’s are set the same but a bit different, AC4400’s the same etc. I agree with the coupling spped at speed step one. I haven’t found the need for one wheel revolution a minute speed. Maybe I’m just too impatient.
Switchers, on the other hand, are set to crawl.
Tilden
I know this is an older thread, and the questions you have might have been answered by now, but in case anyone else may have these questions…
If you’re planning to run any of the locos in your fleet in multiple unit consist, you want to program the CV’s so that they all react the same. Otherwise, you may program individual locomotives to run however you want. Many people would argue, that different makes are difficult, or impossible to match to others. This is the beauty of DCC programming; matching speed tables, and acceleration/deceleration to all locomotives, to run together at will.
If a set of two locomotives consisted together, are an Athearn, and a Kato, the result of drivetrain drag, energy consumption, and gear ratio, cause one loco to push and one to pull, which puts a load on BOTH units, and may cause premature wear on motor and drivetrain parts, aside from the tremendous heat generated from the decoder (breakerless).
Here are the basics:
CV2 = Start voltage
CV3 = Acceleration
CV4 = Deceleration
CV5 = Max Voltage
CV6 = Mid Voltage
Some locomotive motors and/or drivetrains are more efficient than others, and identical locomotives do not always perform the same. For instance, I bought two Athearn SD45T-2’s… Out of the box, one would start moving before the other would, and one of them would coast longer when coming to a stop.
I’ll use this as an example for CV programming.
First, I examine the running characteristics, and determine which ‘likes’ to run and which doesn’t. This is where the acceleration/deceleration is valued. Generally, the one that takes more juice to get moving, will be the the first to come to a stop. I will program CV3 (acc) to the loco that begins moving first, to a value of 2. This will cause a delay, which at the point the slower locomotive begins to move at a higher voltage. In turn, I will program CV4 (dec) to the locomotive that comes to a quicker stop, also to
Good advice. Except some decoders don’t use CV6 for mid voltage.
Also, don’t worry too much about turning the loco into a brick. All decoders have a CV for resetting to factory default values, if you screw it up. When all else fails, read the instructions.
I was not aware that some decoders do not use CV6 for mid voltage. Thanks for pointing that out.