I just don't get it.....

[LIRR]

I have a Bachmann F7 & a Bachmann RS3, both (HO) sound-equipped. I speed matched them and ran them as a consist. They've been working just fine for months. All I did was assign new addresses to match the cab numbers on new shells and changed CVs 128, 129 & 130 to lower the volumes. All others CVs are as they were previously. I cleared all previous consists. The RS3 operates as it did - nice and slow at throttle (NCE Powercab) notch 1 and a bit faster at notch 2. The F7 runs like crap.....starts just barely at notch 1, crawls along at 2,3,4 and higher. Decoder sound revs up accordingly. I want to reconsider them but it's not workin so well......

[peteski]

The problem is either mechanical or electrical (electronic). 

How did you speed-match?  Did you use CVs 2, 6, and 5, or the full 28 step speed table?  Did you record the CV settings anywhere so you could verify whether some of them got changed on the decoder?

[LIRR]

I put it all aside, did something else for awhile, took,deep breaths, had a beer and went back to it. CVs 5 and 6 were at 48. There's no way I did that......guaran-freekin-teed they weren't 48 before, I had reprogrammied twice writing it down and double checking before I walked away. I reset them back to zero, all is well now. F7 runs as it did, consist is all set. just don't get it. I hate electricity

[tehachapifan]

Weird stuff can happen! Not too long ago, I had a DCC loco that was not being used and sitting on a siding suddenly decide to take off on it's own, at a fairly low speed. The (lone) controller was not even set to that loco's address at the time. Luckily, I was there to grab it before it ran off the end of the short track it was on and off the end of an unfinished area. Never happened before and never happened since, but I've had some settings apparently change on their own from time-to-time.

[mu26aeh]

My O scale friend has 3 engines he put loksounds in.  When you run them separate, they all run great.  Consist them, and all hell breaks loose.  Turn the throttle they go, turn it zero, they keep going.  Turn on bell, bell comes on.  Turn it off, it keeps ringing.  Break consist apart, all engines run as normal.  He has been in contact with Matt at ESU, explained in great detail what settings he has, files downloaded, etc and no one has answers.

[peteski]

I put it all aside, did something else for awhile, took,deep breaths, had a beer and went back to it. CVs 5 and 6 were at 48. There's no way I did that......guaran-freekin-teed they weren't 48 before, I had reprogrammied twice writing it down and double checking before I walked away. I reset them back to zero, all is well now. F7 runs as it did, consist is all set. just don't get it. I hate electricity

I'm glad you were able to get things working again.
While DCC is a very useful system, it actually utilizes miniature computeres which, like a full-size home computer, can sometimes get messed up.  I have seen instances of decoders "blowing their brains out" and ending up with scrambled CV values. This most often occurs when there is voltage spike or a short on tracks.  But there can be other factors that cause this (like zapping the decoder with static electricity, or even cosmic rays - seriously).

So if you are absolutely sure that you did not accidentally changed those CVs while reprogramming your loco using the PowerCAB, then I would blame the problem on one of the causes I mentioned above.  I can tell you from personal experience (I also own the PowerCAB) that I have unintentionally changed CVs when I was not paying attention to what I was doing.

I'm a also curious what sort of speed matching did you perform? If CV5 and 6 are set to 0 that means the loco uses the standard preset speed curve, with just the minimum starting voltage determined by CV2 (if CV2>0).  Not much of a speed curve customization.

[peteski]

My O scale friend has 3 engines he put loksounds in.  When you run them separate, they all run great.  Consist them, and all hell breaks loose.  Turn the throttle they go, turn it zero, they keep going.  Turn on bell, bell comes on.  Turn it off, it keeps ringing.  Break consist apart, all engines run as normal.  He has been in contact with Matt at ESU, explained in great detail what settings he has, files downloaded, etc and no one has answers.

If he uses advanced consist (CV19>0) then I believe the functions in each unit can be customized as to whether they respond to the advanced consist address or the actual address of the decoder.  Maye the function mapping is scrambled?  BUt the speed and direction in advanced consist of all locos is strictly controlled using the consist address.
I agree that what you described makes no sense. But if it's a consist defined in the command station then if the command station was not working properly you could see this type of behavior.

[Doug G.]

One of them thar computer "glitches" y'all hear about.



Doug

[LIRR]

pete,

I "speed-matched" to the "good enough" standard. the 2 units match perfectly at throttle notch 1 and 2, nearly so at notch 3. I run at 1 for switching and 2 out on the main. one loco starts to outrun the other if I go to notch 3 or higher, but I never do so, so it's good enough.

thanks for your help.