Sounds like you have the track wires reversed in the tunnel.
CGW103Sounds like you have the track wires reversed in the tunnel.
How does that explain that sometimes it works normally and sometimes it doesn't? The layout ought to be shorted from the get go.
That said, I don't have a clue as to what would explain it. Randy to the White Courtesy Phone.
Henry
COB Potomac & Northern
Shenandoah Valley
A bit more info would help. Have the locomotives with the problem ever worked OK in the area of the problem? Is the Prodigy System new? Are the locomotives new. Has the Prodigy had problem before this problem.More history of your DCC operations will help. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Probably doesnt. Didnt read very well.
What is really weird is the fact that the loco reverses direction in DCC. If feeders were crossed, you would have a dead short in DCC, not a reversal of direction. Something else is going on here. Is the track in the tunnel simply a straight run? Any turnouts?
Rich
Alton Junction
Hmmmmm...Is there a reversing loop somewhere on the layout??? That might explain the sudden change in direction...
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
tstage Hmmmmm...Is there a reversing loop somewhere on the layout??? That might explain the sudden change in direction... Tom
It's as if CV29 is being activated somehow.
Seems like a problem with the MRC Prodigy system.
can any dcc locos go thru the tunnel without a problem?
greg - Philadelphia & Reading / Reading
Did he not say 'wireless'? That has me thinking 'multipath' as a first knee-jerk response. I don't know enough to substantiate how that would cause the actual issue, though.
Is this in fact happening with DCC data received via the rails? And if not, is there a way to test the track and locomotives using wired DCC data transmission temporarily, to confirm it is a 'logic' issue?
What about the plug to the tender
Could be loose or the Radis on the curve causing something weird in the connection
Overmod Did he not say 'wireless'? That has me thinking 'multipath' as a first knee-jerk response. I don't know enough to substantiate how that would cause the actual issue, though. Is this in fact happening with DCC data received via the rails? And if not, is there a way to test the track and locomotives using wired DCC data transmission temporarily, to confirm it is a 'logic' issue?
On my NCE PH-Pro 5 amp wireless system, I also have cables to tether the throttles to ports along the layout. If the OP has a similar arrangement with his MRC Prodigy Wireless system, it would be worth a try to tether the throttle and see if the results are different.
Since the strange behavior occurs inside the tunnel, there may be signal interference, causing the loco to reverse itself due to erratic CV changes.
richhotrain tstage Hmmmmm...Is there a reversing loop somewhere on the layout??? That might explain the sudden change in direction... Tom Why would a reversing loop cause the loco to change direction? It's as if CV29 is being activated somehow. Seems like a problem with the MRC Prodigy system. Rich
Why would a reversing loop cause the loco to change direction?
Rich,
My thought was that perhaps a temporary short inside the tunnel with the longer locomotives might fool the reversing loop detector to think that it needed to suddenly switch polarity, which is what it does. Granted, a stab in the dark (tunnel) but...
tstage richhotrain tstage Hmmmmm...Is there a reversing loop somewhere on the layout??? That might explain the sudden change in direction... Tom Why would a reversing loop cause the loco to change direction? It's as if CV29 is being activated somehow. Seems like a problem with the MRC Prodigy system. Rich Rich, My thought was that perhaps a temporary short inside the tunnel with the longer locomotives might fool the reversing loop detector to think that it needed to suddenly switch polarity, which is what it does. Granted, a stab in the dark (tunnel) but... Tom
OvermodDid he not say 'wireless'? That has me thinking 'multipath' as a first knee-jerk response.
the wireless handset communicates with the command station, not the loco inside the tunnel. i assume the rf path is not changing, unless he happens to be moving just as the loco enters the tunnel
gregcthe wireless handset communicates with the command station, not the loco inside the tunnel. i assume the rf path is not changing, unless he happens to be moving just as the loco enters the tunnel
Could there be a multiple issue, for example the locomotive bridging the reverser gap while simultaneously experiencing a transient loss of power? That might lead some decoders to 'reboot' in the wrong mode relative to what a reverser is doing at that same time...
If I understand correctly, he has certain locomotives that repeatedly exhibit the problem behavior, but others that don't show it at all. The next question is: is there any commonalty in the decoder types, or installation, or programming, in the 'problem children' that isn't shared by the others?
How many throttles do you have? Could multiple throttles be addressing the same engine? If so, is one throttle in reverse while another is in forward? Could these engines have been in consists that weren't properly cleared?
It takes an iron man to play with a toy iron horse.
Hello All,
This has happened intermittently on my pike due to dirty track with a Bachmann GE 70-tonner with a factory-installed PCB type DCC decoder.
When this unit ran over dirty track it stalled, the lights reversed momentarily- -as if resetting- -then the lights returned to normal, and then the unit moved in the original direction of travel.
This happened over straight track and not the unpowered frogs of the turnouts.
It did not actually move in the opposite direction for any distance as you described.
After the track was cleaned the "problem" went away.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
The only time I've experienced "weird" operations with my MRC Prodigy (not squared) DCC system similar to those the OP has described was when I forgot to assign unique cab addresses to each of my throttles, both tethered and wireless. If you have the MRC WiFi module, that has to have a unique address, too. Otherwise, you'll see all kinds of weird stalling, reversing, speed changes, etc.
Hornblower
Could be an inductance-related problem. I've read that different decoders have different sensitivities to corruption of the DCC signal: https://www.dccguy.com/?p=5762
There is one thing I forgot to mention earlier, and it might be important: the problematic section is powered by an MRC booster (10A / 8A). This is isolated from the main control station, according to the manufacturer's instructions. Checking the connections of the two installed boosters, we found that they did not follow the trunk line layout. I refer to the data transmission line (Cable cat 6) between the control station and these two boosters [Note: the power supply itself of the line (bus) already followed the layout of the main line with the two interruptions due]. Well, by fixing the instruction links via the data cable mentioned earlier, I think the distressing problem has been solved: my loco Bachman 2-10-0 Decapod has traveled the “defective” section normally, either in forward or backward. I will continue testing with the other machines I have, in order to see if that problem, apparently solved, can return in any way. On the other hand, I do not want to believe that a cable connection for data transmission, if it does not follow the logical sequence of the layout, could have such a disastrous consequence. But anyway ... Thank you for the many responses and willingness to collaborate with a stranger in difficulty ... Thanks, again, to those who responded, and a happy New Year to all Forum participants!
are you saying there are gaps in both rails near the tunnel and separate boosters are powering the rails on either side of the gaps?
Yes, Greg. When I did install the two boosters, I opened gaps main track, observing manufacturer's recommendations. Thanks.
I have occasionally seen stalling at circuit breaker or autoreverser boundaries. These only happen once, the first time a loco crosses the boundary after powering up the layout. I figure I might need to play with the trip current for the breakers, as something is mismatched.
If the booster has an adjustable breaker, you might try lowering that. In fact, that's a big booster, so you might consider getting some fast PSX breakers to protect the trackage from the booster at a lower current level.
FoscWhen I did install the two boosters, I opened gaps main track, observing manufacturer's recommendations.
do you know how close in "phase" they are? can you measure any (AC) voltage between the rails separated by a gap? (not the rails on opposite sides of the same tie)
Greg, with the layout shut off, and I doing use one multimeter, it's there no are continuity in the track both parts seccioned by gap.
i'm not asking to verify continuity. with the layout powered, i'm asking if there is a measurable voltage across the gap (there should be 0.0 VAC).
FoscChecking the connections of the two installed boosters, we found that they did not follow the trunk line layout. I refer to the data transmission line (Cable cat 6) between the control station and these two boosters [
because you mentioned the data cable between the command station and bootsters, i'm wondering if there is a slight phase difference between the two boosters.
Yes, Gregc, there are a small difference between voltages of the section controlled by the main (3.5A) and the booster (8A), but not between both bosters.
My layout has the shape of a capital letter E. The base station controls the central leg, while the boosters command the outer branches of the "E".
In the present case, the problematic ex-section of the layout is found in the section that is controlled by one of the two boosters. And there is only a gap before it that isolates the central branch (which I call branch "B") from a section of the external branch "C" of my layout.
FoscYes, Gregc, there are a small difference between voltages of the section controlled by the main (3.5A) and the booster (8A), but not between both bosters
i'm not asking if the booster voltages are different.
i'm asking if their "phases is different"