I have a riddle for you all. I have two brand new Athearn Gensis F9s (DCC ready), an A and B unit. The F9A has a new Digitrax SDH-186MT decoder and the F9B has a new DH-166MT decoder. I installed both myself. I'm running both engines off of one DT400 throttle. The F9A acts very strange. It runs well by itself but if I put the F9B on the tracks it acts very strange. If I start the F9A first it will run and I can adjust the F9B, but the F9A will not react to throttle adjustments until I stop the F9B. If I start the F9B first, the F9A will not start or react to the throttle.
If that isn't weird enough... it seems this is the only engine that it reacts to like this. I took the F9B off the tracks, and tried running the F9A with other engines on the track. No problems! I tried another engine, no problems. I put the F9B back on the track, same issue.
I may have cross programed (programed in ops mode) the engines at one point, as one was on the track and I may have had the other number in the programming feature. The engines numbers are close together. However I reprogramed (CV8=08) both engines and still have the same issue.
Do I have a faulty decoder, engine, or a different problem altogether?
NILE
Sounds like some how they got set up in consist with the b unit as lead. Possible when they were possibly cross programmed. I would just make sure they were not in consist, then redue the programming from start maybe factory reset first
shane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
I have reset both decoders (CV08=0008) and I'm still having the same issues. I even consist them again and un-consisted them to see if that would reset. Right now both decoders are factory settings, so default to address 03. I am running them at the same time off of one throttle, and the same thing is happening. Once I put the B unit on the track, the A unit goes "whacky". Does anyone have other suggestions?
Are you running a Digitrax system ? Sounds like maybe your system may be full of entries. Try deleting (dispatching) all the recent addresses that have been entered into the system. Once it is full, strange things like that can start happening when you try to add a new engine. Instructions to clear the slots ....
https://www.digitrax.com/tsd/KB595/command-station-option-switches-clear-slots-and-fa/
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Thanks for the suggestion, I just tried that and no change. I have a DB150 for my command station and it has been a long time since I released addresses. This is the weirdest problem, as the F9A acts normally with any other engine on the track. But if the F9B is on the rails with a throttle setting, either direction at any speed. The F9A is unresponsive to any throttle changes, if it is moving it stays moving at that same speed... if it is stopped it won't move. This is becoming very frustrating.
I also tried running the F9B with a different engine on the track, it had no affect. So it is only the F9A that is having an issue.
Any one else starting to think corrupted decoder. Like the firmware on it became distorted? The only other thing I could think of trying would be a completely different road number. In the a unit. A very different number and see if it still happens. If it did, I would at that point get a new decode. Just where I would go with this
I will try a different address. I was thinking the same thing that it could be a defective decoder.... but the real riddle is why is only affected by one engine? If I take the F9B off the track then the F9A acts normally. It is one of the craziest DCC things I've ever seen.
Worth a shot NILE. I hadn't thought of it until you mentioned it, but I recall reading here about someone having an issue with a decoder (Paragon 2?) that was tied to the specific engine number. Something to the effect of assigning the decoder the number on the side of that particular engine would alter programming on the decoder, or something like that. Let us know what you find out.
Mike
NILE I will try a different address. I was thinking the same thing that it could be a defective decoder.... but the real riddle is why is only affected by one engine? If I take the F9B off the track then the F9A acts normally. It is one of the craziest DCC things I've ever seen.
While you are at it, check the values of CV21 and CV22.
Rich
Alton Junction
Water Level Route Worth a shot NILE. I hadn't thought of it until you mentioned it, but I recall reading here about someone having an issue with a decoder (Paragon 2?) that was tied to the specific engine number. Something to the effect of assigning the decoder the number on the side of that particular engine would alter programming on the decoder, or something like that. Let us know what you find out.
https://cs.trains.com/mrr/f/744/t/248855.aspx?page=1
I doubt that issue is in any way related to this current issue.
richhotrainI doubt that issue is in any way related to this current issue.
I never would have guessed that one particular locomotive number would screw up any decoder until that previous thread showed it was possible. Thanks for finding that thread Rich. Proves I'm not losing my marbles!
To clarify the situation:
Do the F9A and the F9B run normally BY THEMSELVES?
Does the F9A run normally with all other (non F9B) engines?
Does the F9B run normally with all other (non F9A) engines?
My thought would be one of the decoders is bad. My other suggestion would be, since youve reset both to factory with no improvement, try putting "like decoders" in both units. Such as an nce dasr or d13sr or even 2 esu lok pilots, lok sound decoders. These are just examples of course because I dont know which decoder those locos take. I would also send the 2 digitrax decoders you have back to digitrax and let them check them or fix them. They are under warranty I would assume so they should repair them for free.
Whatever you decide, my suggestion would be to use the same decoders from the same manufacturer in any permanent consist lashup like an AB, ABA or ABBA setup.
Good luck
Remeyer53 To clarify the situation: Do the F9A and the F9B run normally BY THEMSELVES? Does the F9A run normally with all other (non F9B) engines? Does the F9B run normally with all other (non F9A) engines?
Anything is possible here, but I am having a hard time concluding that it is a decoder problem or a conflict between two decoders. Both are Digitrax decoders, one (SDH-186MT) is a sound decoder (F9A) with 21MTC interface and the other one (DH166MT) is a non-sound decoder (F9B) with 21MTC interface. That is a "typical" setup for a two-loco consist with sound in the lead loco and non-sound in the trailing loco. I might be more inclined to think that the decoder could be the problem if both decoders were identical.
NILE has done a thorough job here of describing the problem. The F9A only goes "whacky", to use NILE's term, when the F9B is "on the tracks". Something is apparently amiss when the two F9s are running together on the layout. That tells me that it is a programming conflict of some sort. Consisting? Addressing? I think it is a CV issue.
If it is a consisting issue, I would check CV19, CV21 and CV22. CV19 is the Advanced Consist Address. The value of CV19 should be set to zero if the two locos are not intended to be in a consist. CV21 and CV22 are Advanced Consisting Controls. The values of these two CVs should be set to zero if the two locos are not intended to be in a consist. I would check them and not assume that a decoder reset (CV8=08) had set them to zero.
If it is an addressing issue, any numbering conflict should be resolved by running both locomotives on the short address 03. NILE says he has done this. Even so, I would check the value of CV1 on each loco. I would also check the values of CV17 and CV18 (the long addresss) on each loco just to see what values are present in those CVs.
This may all be a waste of time, but I think that it is worth the effort at this point.
Temporarily swap the two decoders and see if the issue migrates with the decoder.
Pete.
wrench567 Temporarily swap the two decoders and see if the issue migrates with the decoder. Pete.
Thanks for all the recommendations. The F9A engine number is 770 and the F9B is 777. I reset both of them to default. I set the F9B to 777 and I set the F9A to 7000 just to be different. I had the same results, the F9A still would not respond to the throttle if the F9B was in motion.
I started seeing how these engines responded to other eninges, and weird responses. It is just these two eninges. I also reset CV19, CV21, and CV22 to 0 on both engines. That did not change anything.
I am using a DB150 command station/booster and I did recieve a "Slots Full" message. I tried to reset my command station by putting it in OP mode, setting Switch 36 and pressing "c".
I'm getting to the point where I think the decoder in the F9A is just "loopy", any other thoughts?
Thanks, NILE
Oh well, so much for CVs being the issue. Do you by chance have a spare decoder that you can try in the F9A? If you do, don't even bother putting the shell in place. Just test another decoder. That is going to be a real bummer if that sound decoder in the F9A is defective.
richhotrain Remeyer53 To clarify the situation: Do the F9A and the F9B run normally BY THEMSELVES? Does the F9A run normally with all other (non F9B) engines? Does the F9B run normally with all other (non F9A) engines? Rich
From a quick re-read of the prior posts, it looks like he's said a couple of times that the A unit works OK by itself, but not when the B unit is on the track - but (unless I missed it) he hasn't said that the B unit works OK when on the track by itself.
Even though the system has been cleared of consist set-ups, it still sounds like there's some problem there with consists. That's the only way one engine being on the track could affect another engine; they're either in a consist or have the same long or short ID or have one of the consist CVs with same entry.
It can be odd, I use CVP for my layout but an old Zephyr for break-in runs and programming on a circle of track separate from the layout. I recently was trying to program a decoder to ID 104, and found to get it to work I had to program it as long address 0104 to get it to work, even though 127 or lower is supposed to be a short address. I've also had decoders where I've changed say the long address but the short address stayed 03 and my DCC system only recognized the short address.
i do not own any Athearn Genesis engines. The ones I have are all old blue box engines but there was always a problem on them with intermitent shorts between the engines using Kadee couplers as the frames were hot. Not enough to shut them down but you would see sparks at times. If the Genesis frames are hot it may be enough to have an effect on the decoder. Just a thought,
Just a shot in the dark - since it's an A/B consist, where the B unit would never operate alone, try setting both engines to the same address, instead of setting up a consist. But break up the consist on your command station first. Worth a shot maybe
And you'll have to change the CV on the B unit to change the normal direction if you run them connected rear/rear
When we last left our hero.... just kidding. So I sent both decoders back to Digitrax for repair. They returned them and said, "fixed". I don't know what the problem was or what they did to them. This week I tried both decoders in the B-unit and..... same problem. So could this be the circuit board on the Athearn engine? It did work in DC mode before I added a decoder. I tried to contact Athearn tech support, apperently they don't have any. At first they said, sorry can't help its a decoder issue. When I explained I've tried two decoders and two manufacture repaired decoders, then they said get a return number and send the engine in. I am highly annoyed that I cannot speak to anyone at digitrax or athearn. I'm going to try changing the address on the A-unit to a long address and see if that changes anything. I'm also going to reach out to a local club and see if they have a DCC expert who might have some ideas. This has become very frustrateing.
I almost forgot about this thread. So, I went back and re-read through the entire thread.
I don't think it is a locomotive problem because each locomotive runs fine without the other locomotive on the track. But, I would ask this question. Can you test both locomotives together on a DC-powered track without the decoders installed? If so, do they run together without problems on a DC-powered track. I suspect that they do run just fine in that event.
Digitrax has confirmed that the two decoders operate just fine. So, we are back to a programming issue as the culprit. Somewhere, somehow, inside the decoder(s) brain there appears to be a conflict between the two decoders. Consisting? Addressing? Dunno. What would be helpful would be a complete printout of each and every CV in each decoder.
I went to a local railroad club open house and talked to them about my DCC issues. They agreed, that it probably isn't the engine. The gentlemen also said that decoders can get messed up and diagnoses can be a slow process. I reset CV19 and set CV28 to 34, reset the command station and.... same problem.
So I tried the b-unit with my only other engine that has a 21-pin decoder in it. That is an Athearn Gennsis SDP40F.... I had the same result. I tried a few other engines the the b-unit acted the same. So at least now I'm getting some consistancy with the problem. I also switched out some decoders. I put SHD186MT decoders in both F units and they worked as they should. It was when I try an run an engine with an SHD186MT on the track with an engine that has a different decoder, the engine with the SHD186MT does not respond to throttle inputs. I swaped in a HD166MT into the b-unit and the engine worked as advertised. So I agree with Rich, the problem isn't the engine.
SHD186MT: This decoder seems to be an advanced model; does it have speed tables pre-defined? Does this decoder have momentum preset?
While the guys at the railroad club were pretty confident that it could be fixed with finding a CV that is set incorrectly. I'm thinking it might be easier to by two HD166MT decoders... since I know that one worked.
Can someone at the club give you a printout of the CV values in the SDH186MT