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Strange problem with my DCC

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  • Member since
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  • From: Dearborn Station
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Posted by richhotrain on Wednesday, December 30, 2020 7:46 AM

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 

But, how would that cause the loco to change direction since it is operating in DCC mode. Or, is it? Is the Prodigy system suddenly thinking it is operating in DC mode?

Rich

Alton Junction

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Posted by tstage on Wednesday, December 30, 2020 7:19 AM

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

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by richhotrain on Wednesday, December 30, 2020 7:07 AM

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? 

Interesting questions.

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.

Rich

Alton Junction

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Posted by ndbprr on Wednesday, December 30, 2020 7:05 AM

What about the plug to the tender

 Could be loose or the Radis on the curve causing something weird in the connection

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Posted by Overmod on Wednesday, December 30, 2020 6:51 AM

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?

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Posted by gregc on Wednesday, December 30, 2020 2:57 AM

can any dcc locos go thru the tunnel without a problem?

greg - Philadelphia & Reading / Reading

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Posted by richhotrain on Tuesday, December 29, 2020 9:27 PM

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

Alton Junction

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  • Member since
    June 2003
  • From: Northeast OH
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Posted by tstage on Tuesday, December 29, 2020 9:14 PM

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.

  • Member since
    September 2004
  • From: Dearborn Station
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Posted by richhotrain on Tuesday, December 29, 2020 8:31 PM

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

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Posted by CGW103 on Tuesday, December 29, 2020 7:25 PM

Probably doesnt. Didnt read very well.

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Posted by RR_Mel on Tuesday, December 29, 2020 7:25 PM

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/
 
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I'm beginning to realize that aging is not for wimps.

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Posted by BigDaddy on Tuesday, December 29, 2020 7:00 PM

CGW103
Sounds 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

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Posted by CGW103 on Tuesday, December 29, 2020 6:48 PM

Sounds like you have the track wires reversed in  the tunnel.

 

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Strange problem with my DCC
Posted by Fosc on Tuesday, December 29, 2020 5:59 PM
Greetings,
 
I have a strange problem in a tunnel on my layout. My locomotives AC 6000 BLI and J1 BLI, for the first time on that specific tunnel, unexpectedly stop and reverse, even  though i didn´t touch my wireless handheld to stop and reverse the run . On the second attempt both locomotives goes through tunnel normally.
 
And I have a small Bachmann Decapod steam that has the same problem in that tunnel.  In this case, the loco doesn't traverse through tunnel no matter how many times I've tried.  I noticed that this probelm happens with 2-10-0 at 3 different points, and the same does not happen with the previous two.
 
After that, i substitute "Decapod" for another one and it runs smoothly.
I double checked my electrical scheme, apparently, everything is normal.  My MRC Prodigy Wireless System handheld LCD didn´t indicate any overload or short circuit. Anyone could help me?
 
Thanks.

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