DCC HELP REQUEST

[carlso]

I am brain storming here folks, so please bare with me. That is a scary thought, you may smell the sawdust burning. I have looked through Digitrax website and have found nothing and I have looked through TRW & TB with no success. So if any of you have experienced this same issue or know of an article, please let me know.

Facts are;

System is a Digitrax Super Chief DCS 8amp Command Station/Booster
A PS2012 20 amp power supply, as recommended by Digitrax
All throttles ar DT402D Duplex units

This is set up on our club layout and last Wednesday  2 or 3 of the operators began experiencing the same problem, just all of a sudden. This set up has been working well for 4 years now, or up until last Wednesday.

Situation:

The 2 or 3 operators started having the same problem, with no warning, and that is when turning their throttle to the setting of "1" the locos would take off as in run 8 which was actually full dcc throttle. They were able to stop them but again on 1 they take off like a ruptured duck. Their lighting functions acted screwy as well.

I put one of my locos on the track with my Duplex throttle and did not experience the problem.

In my case and at least 3 or 4 of the other locos, the decoders were Digitrax and one of them, a Model Power steamer, I have no clue as to brand of decoder. They all went to JMRI and reset their decoders to factory and then re-programmed the 4 digit address but still had the problem.

I have read about this but can not, in my pea brain, remember where. Is it a decoder problem or a command station problem. Oh, I forgot to mention that the command station was "dumped" to remove all addresses.

Any information or suggestions would be greatly appreciated,
Carl

[Mike C]

  I use an NCE system , but don't I remember something about doing a command station reset ? Like doing a decoder reset but for the command station .

[peteski]

This sounds like a command station problem, not a problem with all the decoders.

Maybe it is a speed-step mismatch?  Maybe the decoders are set for 28/128 steps and the command station somehow got put in a 14 step mode?

[carlso]

thanks guys for the input.

Mike, we dumped the command station to remove all the addresses held in memory, but maybe a re-boot of the command station back to factory settings would be the solution.

Pete, I, obviously, did not think about a speed-step mismaatch. did not know that could be a problem.

I shall read the on-line manuals on D-trax website, that should be exciting.

Carl

[POVC]

When was the last time you replaced the CMOS battery in the command station?

4 years is probably passed the life expectancy of the battery; our club tries to replace ours every 1 or so.

Tim

[mmyers]

Tim,
 I have new batteries to install before Bedford.

If you do replace the battery and I suggest doing so, remove the current battery completely and let the unit sit for a few minutes. Install a fresh battery and go ahead and power up after reinstalling the cover and wires. this will cold boot the command station. it will be in its new- just out of the box default state. Set the option switches the way you want. i suggest closing option switch 5 and closing option switch 44 if the unit is a command station.

Martin Myers

[carlso]

Tim & Martin,

thanks for that suggestion. I use NCE at home and the D-trax is on club layout. I did not even know there was a memory battery in the command station until I read about it a couple of hours ago.

I shall change OPSW 5 to "c" and the #44 seems to be a good bet also.

One question comes to my mind and that is if I was the manufacturer why would I set "t" on #5 OPSw but recommend that it be changed to "c". Wouldn't it seem logical to set the default as "c" at time of initial programming.

Again, thanks for your input as I feel that you are both very knowledgeable regarding D-trax.

Carl

[mmyers]

Darn good question. Wish I knew the answer. I believe it would onl make a difference on a multiple DCS layout. I've never had a problem leaving Op Sw 5 thrown on a single unit layout.

[carlso]

Update for today

I replaced the CMOS battery today, even though it did not need to be. It tested @3.1V and that is after we have used the set up for 4 years. Granted we do not do a great deal of running but I would have thought the battery would begin to fail just because of its age.

We discovered the loco number giving fits  was on 3 different throttles and once we purged the loco stack in command unit and dispatched from throttle, the loco ran well.

At any rate, I set the OPSW #5 to (c) as recommended by D-Trax and one of you, #14 to (c) upon suggestion by D-trax, and finally #44 to (c) as well. The system ran OK. the Model Power steamer with a D-Trax Z125 (I think) ran well initially until he passed over a certain turnout in one place on the layout. Something must be shorting because that is when the decoder looses its mind and only after using JMRI on it and re-programming will it respond normally. What it does is gallops away at full throttle when throttle is turned to step 1.

I would say it is the steamer, you know how finicky their pickups usually are, but this same issue hit 3 different diesels last week. We continue to work on the problem.

Carl

[peteski]

Model Power steamer with a D-Trax Z125 (I think) ran well initially until he passed over a certain turnout in one place on the layout. Something must be shorting because that is when the decoder looses its mind and only after using JMRI on it and re-programming will it respond normally. What it does is gallops away at full throttle when throttle is turned to step 1.

I would say it is the steamer, you know how finicky their pickups usually are, but this same issue hit 3 different diesels last week. We continue to work on the problem.

Carl

Why not try some troubleshooting/detective work?  Since you use JMRI I suspect that you have a full CV dump of the decoders for each loco.  When a loco blows its brains, set it on programming track and have JMRI read out all of its CVs. Then compare the good and blown set and see which CVs got changed and to what values.  If not for anything else, just out of curiosity.

[carlso]

Peteski,

that sounds like a good idea and if it were my loco that's what I would do. The person it belongs to does not use JMRI anything, doesn't even attempt to learn and use it, most likely doesn't want to. So I will not attempt to help him anymore, unless he asks. Our layout repair shop has latest version of the JMRI but we do not have any internet available and no printer to dump the decoder settings. The next time he brings it and it is responding properly I'll attempt to print out the CV's and then if he has the problem again we can dump the decoder again and see which if any CV's changed. We need to solve the problem, especially if it is going to have an affect on diesels as well, because we have the Fair Show coming up at end of September.

Carl

[John]

Something must be shorting because that is when the decoder looses its mind and only after using JMRI on it and re-programming will it respond normally. What it does is gallops away at full throttle when throttle is turned to step 1.

hmmmm .. from what I read, your problem seems to be around the switch .. how is it wired?  check to see if there is something other than DCC wired to it ..  i think you should look at your wiring ..

[carlso]

Thanks John for the suggestion, not a bad idea. Funny thing is we had a "run/fun day" today and this operator as well as 2 or 3 others ran across the same switch and area of the layout without experiencing any problems what so ever. Of course they were damned diesels. Oh well, heck. I will run a steamer over the area next time and we shall see if it has a problem.
Personally, I think it something in the Model Power with added DCC. ? ? ?

Carl