I have a TCS CN decoder in a split-half Atlas N GP35 locomotive.
The engine runs somwhat but I can essentially only program CV1. I cannot read/write CVs 4, 5, and 6 as well as some others. Once in awhile, I can read CV5 and simply get the loco number but cannot change it.
I use a Digitrax Zephyr DCS50 in PAGE mode on a dedicated programming track.
Is there a compatibility issue or ....? How do I program the 3-point speed curve using CV4, CV5. and CV6?
Normally if it's not a sound decoder, the Zephyr should be able to read any decoder's CVs.
With a Zephyr, you normally don't need to use CV1 to enter the engine ID number. After selecting "page mode" just click on the engine no. entry button - like you'd do for calling up an engine to run it. You can choose a 2 or 4 digit number. Enter the number you want, and hit the button to write it like writing (programming) a CV. On a 4-digit number, the Zephyr automatically calculates the amounts to put in the long ID CVs (17 and 18 IIRC).
CV 4 isn't used in any speed curve settings. It's the stopping momentum - how long the engine will drift before coming to a stop.
Here are the CVs you'd normally use to control motion:
CV2: Start value for the engine. Generally, you'd start at zero and increase it a little at a time until the engine starts to crawl at step 1.
CV3: Starting momentum. Time it takes for the engine to get up to the speed you've set with the throttle.
CV4: Stopping momentum. If you put the throttle to zero (or the Zephyr direction switch to "neutral"), this controls how long it takes the engine to coast to a stop.
CV 5: Top power. This controls the top speed of the engine. Setting it to zero or 255 means when you turn the throttle all the way up, engine runs at full possible speed. If you reduce it to say 128, the engine will only go half as fast at any speed setting.
CV 6: Midrange speed. If you want to set a straight-line speed-curve, you don't really have to enter anything here. It is handy if you want to have the engine run smoothly at low speeds but still be able to go fast...you could set CV 6 to 65 and CV 5 to 200 for example. The engine in the first half of the throttle range would be going fairly slow, but would speed up considerably if the throttle were set up all the way.
Note that often, even if you can't read back a CV, you can in fact still change it. You just can't read it back to verify it.
Just a base to start with, I'd suggest trying this:CV2: 0
CV3 and CV4: 10
CV5: 200
CV6: 100
Easy to remember if you can't read them back, and you can kinda go from there adjusting them up or down as needed.
wjstix Normally if it's not a sound decoder, the Zephyr should be able to read any decoder's CVs. With a Zephyr, you normally don't need to use CV1 to enter the engine ID number. After selecting "page mode" just click on the engine no. entry button - like you'd do for calling up an engine to run it. You can choose a 2 or 4 digit number. Enter the number you want, and hit the button to write it like writing (programming) a CV. On a 4-digit number, the Zephyr automatically calculates the amounts to put in the long ID CVs (17 and 18 IIRC). CV 4 isn't used in any speed curve settings. It's the stopping momentum - how long the engine will drift before coming to a stop. Here are the CVs you'd normally use to control motion: CV2: Start value for the engine. Generally, you'd start at zero and increase it a little at a time until the engine starts to crawl at step 1. CV3: Starting momentum. Time it takes for the engine to get up to the speed you've set with the throttle. CV4: Stopping momentum. If you put the throttle to zero (or the Zephyr direction switch to "neutral"), this controls how long it takes the engine to coast to a stop. CV 5: Top power. This controls the top speed of the engine. Setting it to zero or 255 means when you turn the throttle all the way up, engine runs at full possible speed. If you reduce it to say 128, the engine will only go half as fast at any speed setting. CV 6: Midrange speed. If you want to set a straight-line speed-curve, you don't really have to enter anything here. It is handy if you want to have the engine run smoothly at low speeds but still be able to go fast...you could set CV 6 to 65 and CV 5 to 200 for example. The engine in the first half of the throttle range would be going fairly slow, but would speed up considerably if the throttle were set up all the way. Note that often, even if you can't read back a CV, you can in fact still change it. You just can't read it back to verify it. Just a base to start with, I'd suggest trying this:CV2: 0 CV3 and CV4: 10 CV5: 200 CV6: 100 Easy to remember if you can't read them back, and you can kinda go from there adjusting them up or down as needed.