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Unusual DCC circuit request...

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  • Member since
    May 2009
  • 61 posts
Posted by RF&Prr on Sunday, March 21, 2010 7:32 AM

 Jim,

1 - The DCC signal is the same whether it is in the roundhouse track or on the mainline:  Yes, I know

2 - All engine addresses are sent whenever a speed change or keep-alive is sent.  Yes, I know.  When you select a stall track that section of track will have the DCC signal present when moving engines in and out.

3 - You will need to isolate each stall(transponding).  Stall tracks are isolated and already have optical detection

4 - Transponding will give you only the engine number that is in the stall.   I do not intend to buy / replace 40 plus decoders that can do transponding.  This can be done using the DCC signal, not replacing decoders.

5- Again, transponding will tell you if there is an engine.  Again, I do not intend to buy / replace 40 plus decoders that can do transponding.   There is a way to do this using the DCC commands on the track and not having to purchase transponding decoders.

 

Yes, most of the doors are visible, (but being able to see the engine number would not be easy) and some stalls are not visible from the operators position.  

 To me this is just a conveinent way of keeping track of your engines in the stalls, so when you return to operating after several weeks and you have forgotten which stall has which engine in it. 

John

  • Member since
    January 2001
  • From: SE Minnesota
  • 6,847 posts
Posted by jrbernier on Sunday, March 21, 2010 7:16 AM

RF&Prr

 I do think it would be possible without transponding decoders.  This is how the circuit would need to work, keeping in mind this is for a roundhouse or other building housing multiple engines....but would be limited to one engine per track.

  I belive most people in this situation (a roundhouse) do not keep power on to all tracks at all times, just turn the power on the track that needs it to move a particular engine in and out af the building / stall.

1.  Detect when DCC signal is being applied to the track

2.  If a DCC signal is detected, then begin reading the signal and "strip" the engine address being sent

3.  Store and lock this engine number in a register and display that number on numeric LEDs

4.  Working in conjunction with an optical detector, it can then sense if their is actually an engine present

5.  If no occupancy is being detected on that track, then display nothing

I believe it would be possible to do this,  just how to "strip" the byte data from the DCC packet containing the Engine address would be the hardest part (for me anyway).

 John

1 - The DCC signal is the same whether it is in the roundhouse track or on the mainline:

2 - All engine addresses are sent whenever a speed change or keep-alive is sent.

3 - You will need to isolate each stall(transponding). 

4 - Transponding will give you only the engine numbe that is in the stall

5- Again, transponding will tell you if there is an engine.

  Like Randy suggested, transponding decoders with a detector on each stall track would be the best way to go  here.  I guess I am curious why one wants a display with each engine number in each stall - Is the roundhouse doors not visible to the operator?

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

  • Member since
    May 2009
  • 61 posts
Posted by RF&Prr on Sunday, March 21, 2010 6:15 AM

 I do think it would be possible without transponding decoders.  This is how the circuit would need to work, keeping in mind this is for a roundhouse or other building housing multiple engines....but would be limited to one engine per track.

  I belive most people in this situation (a roundhouse) do not keep power on to all tracks at all times, just turn the power on the track that needs it to move a particular engine in and out af the building / stall.

1.  Detect when DCC signal is being applied to the track

2.  If a DCC signal is detected, then begin reading the signal and "strip" the engine address being sent

3.  Store and lock this engine number in a register and display that number on numeric LEDs

4.  Working in conjunction with an optical detector, it can then sense if their is actually an engine present

5.  If no occupancy is being detected on that track, then display nothing

I believe it would be possible to do this,  just how to "strip" the byte data from the DCC packet containing the Engine address would be the hardest part (for me anyway).

 John

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Saturday, March 20, 2010 11:11 PM

 This is not really possible. Engines that are not selected on any throttle do not have any commands being sent to them. The only way to do what you want is to use Digitrax Transponding or Railcom. Any loco with a transponding or a Railcom decoder will be able to feed back its address if power is applied to the track.

                                --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    May 2009
  • 61 posts
Unusual DCC circuit request...
Posted by RF&Prr on Saturday, March 20, 2010 10:36 PM

  I am interested to know if anyone has done this.....

Is it possible to build a circuit that will read a DCC signal and extract just the engine address only? This circuit would need the ability to read all engine addresses being sent to a roundhouse stall track. 

  My application would be for a 12 stall roundhouse, so one knows which engine is currently in which stall.  On my control panel would be twelve - 4 digit numeric led displays, numbered according to the stalls.  These 4 digit displays would then let me know which stall engine number xxxx is currently in.

 John

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