DCC failure a`AMENDED, we GOT IT!

[Blind Bruce]

Thanks to all for the help. Per instruction, I reset the Zephyr command station. The problem loco has been running the circle for an hour now.

 

 

 have an HO 2-6-0 (made in slovakia) that a friend installed sound in. It is  PROBABLY a TCS as he is a TCS dealer. The loco runs and sounds great but every 40 seconds or so, it stops running. The lights and sound are still there but it will sit still until I nudge the throttle either up or down. Then it runs for a short while again. It does this in forward or reverse. If I move the direction lever (Zephyr) to center, the loco moves forward then stops. The dealer/friend is hard to get so I would like any suggestions you may have.

[Blind Bruce]

Oops, I should have said "the motor decoder is TCS" The sound decoder is Digitrax, 2 decoders.

BB

[UpNorth]

... or  you could have a TCS decoder plus an added sound decoder. Got to find out more.

Clean track and wheels ?.  Binding mechanism at slow speed ?

These Mehano 2-6-0 are all plactic frame, wear out and start binding.

[grayfox1119]

Bruce, if this is occuring in the same locations on your track, then this is pointing a finger at dirty track/s or connections for rail power at those locations. As David pointed out, the charged capacitor on the sound decoder will hold enough voltage to allow sound until it discharges. I am suspicious however that you mentioned that the lights stay on. If you are having poor electrical pickup, the lights should dim. I wonder if your gearing on the loco is jambing somewhat?

[UpNorth]

Oops, I should have said "the motor decoder is TCS" The sound decoder is Digitrax, 2 decoders.

BB

Are both decoders in the tender ?

[Blind Bruce]

I'm pretty sure it is not dirty track. I cleaned the entire oval (test track) with my Mike and a CMX, the Mike and other locos exibit no problems, and this loco stops all over the track, not in just one spot. Also, when it is stopped, I can leave it alone for a couple of minutes and the lights and sound remain constantly on. I suspect a bad decoder.

[jeffrey-wimberly]

Sure sounds like a decoder problem to me.

[jfugate]

The other thing to always, always, ALWAYS make sure of is that CV29 has analog conversion mode turned OFF.

If analog conversion is ON, then all bets are off. DCC locos will do all kinds of wierd behavior thinking it has straight DC on the track ... run sometimes, sometimes not run, take off at full speed when nobody's looking ...

[CSX Robert]

I have to second Jeffrey's opinion, it sounds like a decoder problem. With any of the other problems mentioned(dirty track, binding mechanism, intermittant short), it would not make sense that simply adjusting the throttle would cause the engine to resume running(if it was a binding mechanism, I could see adjusting the throttle up would help, but not adjusting it down).

[retsignalmtr]

i have had this happen to me on my home layout and at my club. it's also happened to several members of my club. in our situation it was an easy fix. somehow our system was running another loco at speed 0 with the same address. probably one that was not properly dispatched. when we would start the loco it would run for a few seconds and stop. then start moving again after a few more seconds. this start and stop cycle went on until i figured out that when the command station sent out an update message for the loco that had speed 0 it caused my loco to stop. then when it sent out another update for my loco it would start to move again. i was able to clear the memory of the command station to remove any loco that was in its memory. this will not affect the decoders of the locos on the layout but you will have to reselect any loco you are running and it will de-mu any locos running together. the instructions for doing this will be in the manual for the zepher. i think it is called an option switch and it is #39 on my empire builder. i hope this helps.

[BRVRR]

Bruce,

I don't think it is dirty track or a decoder problem.

You don't say, but if you have throttles on the jump ports of your Zephyr, make sure that the loco you are running on the main throttle isn't dialed up on one of them. I have run into the same problem your describe on occasion. Having the same loco on two throttles causes the problem for me on my Zephyr. Something about 'update' packets, I think. Once the duplication is cleared up everything returns to normal.

That said, in one stubborn case, I had to reset the command station. Something to do with the loco being part of a consist I think.

Hope this solves your problem.

[Blind Bruce]

OK, there are no external throttles, I am using only the Zephyr. It is a test track so no DC locos are present. Should I still check CV29?

[UpNorth]

what have you got to loose. Just confirm you're  running 2  or 4 digit address and then correct the analogue conversion. If your running 2 digit use CV29=2  if 4 digit use CV29=34

[BRVRR]

I don't think its a question of DC or DCC. Most TCS decoders will run on either one. Are you sure its a Digitrax sound decoder and not Soundtraxx? Is it a sound only decoder. If not other things might be wrong. One other thing. The TCS decoder can be locked to prevent changes. If it is not (or does not) respond to changes in OPS mode that might be your problem. Ditto for some of the Soundtraxx decoders.

To be safe, it is best to program one decoder at a time. Not all manufacturers program the same way, nor do they reset the same way. Your best bet is to set the addresses, one at a time on a programing track. I don't know how many times I have loused up the settings on dual decoder locos by forgetting this.

Once the addresses are set you are still taking a risk programing in OPS mode with both decoders on the same address. It is best to separate them slightly so that you can get things the way you want them and then match the addresses. This is what Soundtraxx recommends.

By the way, to reset a TCS decoder, program CV 30 or CV 8 to 2. Then turn off the power and restart.

Once we know for sure what sound decoder you have we can come up with a reset value for it.

It still sounds like some kind of a duplication of locos. You can start on loco with one address, switch to another address and run another with the Zephyr. While you are controlling the second, the first one will carry on without direction until you call it up again and stop it.

To eliminate the possibility of duplication, reset the Command Station. For a Zephyr the procedure is: 1. Press the PROG key. 2. Press the SWITCH key. The Switch Indicator Dot will blink to indicate you are in Option Switch configuration mode. 3. Enter 036. 4. Press the c/- key. 5. Press the EXIT key.

I wish you luck. Keep checking. It is unlikely that both decoders would fail at the same time. One or the other should respond.

 

[Blind Bruce]

I don't mean to open a can of worms here but I do not understand. If I have two decoders (I suspect that I have), and they have the same address, how do I select which decoder to program? The same CV on one might control a certain function on one but an entirely different function on the other. I might want to change the bell volume and end up changing the accelleration rate (example only). I know that the engine responds to address 851.

Since someone else did the install, I don't know the decoder(s) make or model number. Is this necessary to know?

[BRVRR]

Bruce,

There in lies the 'catch' when using two decoders.

Your first order of business is to check and see how many decoders are in the loco. If it's a steamer, they are probably in the tender. If its diesel, who knows. Contact your supplier/installer and get the straight poop from him/her. They should know what decoders are in the loco and be able to give you some information on programming them.

Most decoder manuals are available on line. Once you know the manufacturer(s), just go to their site and download the manual.  

One way is to remove, or unplug each decoder separately and program the remaining decoder in place. That is essentially what I do. TCS and most Soundtraxx decoders use the 9-pin plug so unplugging one or the other shouldn't be a problem.

The locking feature I mentioned earlier can be useful in dual decoder systems. Set up the motor drive decoder first (TCS), lock it, then plug in the Soundtraxx (or other sound decoder) and program it to your heart's content.

Most of my dual decoder locos are actually AB/AA/ABA diesel sets. While the decoders are coupled together for electrical pickup, I can separate the units and deal with the decoders individually. I sometimes program a slightly different address into the sound decoder, then MU it to the set. Then I program the sound decoder to my liking in OPS mode on my DT400.

Dual decoder installations give you the best of both worlds. Great sound and motor control, but the benefits come with a price, complexity.

I have probably muddied the waters, rather than clear them, for you. Find out which decoders are in the loco. Thats the first step. Ask the installer, or pop off the shell.

Good luck,

[Phoebe Vet]

I vote for looking for a mechanical problem.  Something binding in the drive train.  Sometimes when you disassemble it to install the decoder something is a little out of place when you reassemble it.  It doesn't take much.  Damaged insulation or otherwise exposed decoder wire can do it as well.

[UpNorth]

I don't mean to open a can of worms here but I do not understand. If I have two decoders (I suspect that I have), and they have the same address, how do I select which decoder to program? The same CV on one might control a certain function on one but an entirely different function on the other. I might want to change the bell volume and end up changing the accelleration rate (example only). I know that the engine responds to address 851.

Since someone else did the install, I don't know the decoder(s) make or model number. Is this necessary to know?

If who ever set this up for you was smart he setup both decoder for 4 digit, 851. He should also  have given each decoder a separate 2 digit address (50 for the motor and 51 for sound, as an example). 

You would  change CV29 of loco 851 to reflect 2 digit addressing. Both decoders will change to 2 digit (because they share the address) and both decoders will now show up.  You now do your CV changes to decoders 50 and 51.

Once CV changes are finished,  you switch both decoders back to  4 digit (CV29, do this to both decoders 50 and 51)  again and your back to engine 851 on both decoders. 

But you should confirm this with he who did the install. 

[CSX Robert]

Bruce,
I see that you resolved your problem, but I thought you might be interested in knowing for sure what caused it. I believe Allan had the answer with the jump port. Even if you are not using the jump ports, what probably happened is at some point you accidently assigned the engine to one of the jump ports. I tried this on my Zephyr, and it acted exactly how you described - I could start the engine on the main throttle, and after about 40 seconds it would stop. Any adjustment made to the main throttle would get the engine going again.

What is happening is you have two throttles controlling the same address, and when the Zephyr polls the jump port and doesn't see any voltage there it sets that engines speed to zero, then when the Zephyr sees a change on the main throttle, it sets the engine it is controlling to that speed.

If this is what happened, when the engine was assigned to the jump port and you assigned it to the main throttle, the Zephyr should have prompted you with the "StLo" message, which means "Steal Loco?" If you see this message, the engine you are trying to control is assigned to another throttle. I don't think "steal" is the best choice of words here, Digitrax should have used "share," because when you steal an engine, the other throttle still has control of it also.