Losing control of my Deltic

[NSE456]

Hello,

 

I have a Class 55 Deltic that comes with the HM7000 sound decoder installed.

I have the loco running on a Hornby Select DCC controller and It was happy days at first but twice now I've completely lost contact with the locomotive.

The first time was before I paired it with the app and while other locos with traditional DCC decoders worked fine, this one was nowhere to be found on its address or on address 3 all of a sudden, and even the app couldn't find it. I ended up resetting the CV8 to get the controller to reconize it again and then the app was able to see it as well.

The second time it went wrong was while running, the only settings I changed on the app was the volume, I left it in DCC controller and it had been fine for a number of short runs but today while running it just vanished from the controller, even hitting the Emergency Stop button which halted everything else on the tracks had no effect on this Deltic it just kept going. I booted up the all (which I havn't really used at all besides a quick look and adjusting the volume) and it wouldn't connect on there either.

Again I reset CV8 with nothing else on the track and it looks like we're back to new condition again, its awake and responding with sound and movement on address 3 again.

When it connected to the app it did an update, but the problem has occured before and after the update now.

Not sure what to do really I like this loco a lot but I don't want to have to keep resetting it, and its a bit worrying to think it can just runaway and seemingly anytime with the Emergency Stop button not being able to halt it.

[LTSR_NSE]

There have been reports of (an as yet unidentified glitch) causing HM7k decoders’ CV19 to be altered.  If your issue happens again you might like to try reading CV19 (before resetting CV8) - as if this is the fault, simply returning CV19 to the correct value is easier than resetting everything.

Edited March 16 by LTSR_NSE

[Britannia Builder]

After experiencing the CV19 corruption when running under Railmaster I did wonder whether the RM red 'all stop' button would have stopped the runaway loco (in fact I used my physical emergency power off switch), but it sounds as though it wouldn't have done. Presumably the controller sends out a stop to each address that it knows about, rather than some generic DCC 'stop all' command that would have covered the corrupt CV19 address?

Regards, John

[Rog RJ]

If you have the latest firmware then pressing and holding the STOP button for 3 seconds or more will cut track power, rather than just sending the " All Stop" command.

Personally, I think 3 seconds is much too long in a run away situation.

[NSE456]

Tbh I never really thought much into how the stop works, but idk I also got a giant power switch thats easy to press as a backup.

I'll do some more running and if it does it again I'll take a look at the CV19.

Even if they do fix the glitch eventually its a bit of a nuisance. Seeing as its new I feel it should have warranty coverage. I'd rather keep it and hope a firmware update sorts it later down the line, but I also don't want to end up in a position where its still got a problem and I'm not covered anymore.

[96RAF]

The Select at latest revision has 2 stop modes. One that sends an all stop command but leaves the track live and one that cuts track power.

The way your train reacts to these is dependant upon the decoder. If it has a stay alive and track power is cut then it will continue until the capacitor is depleted. If it doesn't have a sty alive then it will dead stop. Upon receipt of an all stop command then the train will stop immediately under CV4 conditions.

CV19 corrupting will stop the decoder responding to DCC commands as it invokes a consist address. Runaway is normally because CV2 has corrupted to a high value - much like dropping the clutch in your car with the engine at max chat. 

It you have the latest decoder profile state then await the fix which is being worked. Often a simple trick that works when DCC control is lost (apart from the above resons) is to rock the loco off the rails at one side for a moment. This often restores control.