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
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.
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).
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
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.
RF&PrrAgain, 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.
A German company (Dietz Modellbahntechnik) has proposed the SUSI (Serial User Standard Interface) protocol for DCC decoders, and the NMRA has assigned an interim Recommended Practice to this technology which will use CVs 897 through 1024 to control additional advanced functions; however, no other DCC manufacturer has yet adopted the SUSI specification. If it does ever come about, this may be what you need..
RF&PrrIs it possible to build a circuit that will read a DCC signal and extract just the engine address only?
John, One way would be to read each individual isolated track with JMRI Decoder Pro. I don't know how you would streamline the process or display for the 12 tracks though. It would probably require a polling type of software program. Just a thought.
RF&PrrIs 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.
Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam
it would be easier to fit a couple of webcams and look at whats in there. ??
locoworks it would be easier to fit a couple of webcams and look at whats in there. ??
Miniature video cameras would work, but if you have similar engines which you can only distinguish by road number, they probably won't have the resolution you would need to read the numbers.
What would the prototype do? My guess is, they'd get a whiteboard and write the engine numbers on it. In the steam era, it would be blackboard and chalk.
It takes an iron man to play with a toy iron horse.
tricky_trev...Have you got any PIC programming know-how or a PR3? You need to monitor the DCC packets on the layout (very easy to do), and monitor the feeder droppers for the stalls with a sensitive current detector (i use a simple op-amp design). if you monitor the packets along with the status of the current in the stall (train entering =1 and leaving =0), you can have a very reasonable and accurate guess of what loco is there. store it in a latch/memory or text file on the PC and you will "remember the status". sounds like a cool project i should add to my layout as i have the same problem...
tricky_trevengine #1 would need to do do the same acceleration as engine #2 to confuse the system, which is almost impossible.
idea 'B' ? assuming you are all diesel stock, just select likely numbers and switch the lights on and off or off and on to confirm the correct loco is selected. i'm sure you will be able to tell what numbers go with which loco types?? so it may take a few trys to get the right number??
Well, I am mostly steam, but do have several diesels too. I have a good understanding of electronics and am quite computer literate (MCSA). The cost of this roundhouse engine detector is going to be a factor for me, so I am thinking that trying to work out a circuit to cypher the DCC loco address is going to be difficult, tricky and costly to do.
Now , for my next idea that is totally independent of any DCC system....
Suppose you use an IR emitter detector scheme. IR emitter (facing downward) in each engine set to a specific freq. and have the detectors mounted in the stall tracks. You could build the emitter circuit small enough to reasonably fit into a steam tender, but a diesel would be harder to do. If each engine had it's own specific freq. then the detector would know the engine #. The detector circuit would have to be able to detect all frequencies used and then transmit the proper decimal code to the LED display drivers based on which freq it has detected. Seems possible and not to costly. Any thoughts?
John,
I agree, getting away from using the DCC as the detection mediem is a good idea. What about using small RFID tags(like those in pets) They are small enough to put in an engine and can be read by a small proximity scanner - there is lots of HW/SW for this stuff.
There are some people working on using RFID in model railroad applications. The biggest hurdle so far is the range - 2-3" of seperation in HO scale it still close enough that multiple tags respond to the sensor.
Another option is Uhlenbrock's LISSY. This is an IR transponder system a small chip with a unique ID, like an RFID tag, is installed on each loco and an IR LED tramsmitter/receiver pair goes between the rails. As the transponder passed over the track sensor it broadcasts its ID. The transponder cna be programmed like a mobile decoder to whatever ID you want to use, the fixed side of the system can each monitor two tracks (2 sets of sensors connect to each box). It's a Loconet device (yet another bit of wondeful gadgetry that works with Loconet but is not a Digitrax product) and support for it is in JMRI. WHat ther isn't is much information in English, which is rather wierd. ESU offers their site in multiple languages, Uhlenbrock is German-only. The one site I foudn with any information in English is 6 years out of date, but they do mention at the bottom 4 dealers in the US. The Lissy manual on the site is the German one, but the pictures give a pretty good idea how it works and how to install it. http://www.rjftrains.com/intellibox/uhlenbrock.htm I wish there was more information available - this would seem a great way to go, a transponding system that is independent of the DCC track signal. Short range, and localized to a section of track (point detection vs "anywhere in the block" which is exactly what you'd want on roundhouse stall tracks.
RF&PrrSuppose you use an IR emitter detector scheme. IR emitter (facing downward) in each engine set to a specific freq. and have the detectors mounted in the stall tracks. You could build the emitter circuit small enough to reasonably fit into a steam tender, but a diesel would be harder to do. If each engine had it's own specific freq. then the detector would know the engine #. The detector circuit would have to be able to detect all frequencies used and then transmit the proper decimal code to the LED display drivers based on which freq it has detected. Seems possible and not to costly. Any thoughts?
RF&Prr 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
If I were going to try something like this, I think I'd see about doing it with RFID. Reader/Writers are cheap and so are the RFID tags-- you probably would want the "grain of rice" type tags which could be located nearly anywhere on the loco and painted any color you like. Then you would have a unique ID associated with every loco which you could then read with one or more readers wherever you want them, and manage the data read however you like.
rrinkerThere are some people working on using RFID in model railroad applications. The biggest hurdle so far is the range - 2-3" of seperation in HO scale it still close enough that multiple tags respond to the sensor.
No way-- you can go an easy 8 to 15 inches with el-cheapo off-the-shelf stuff. I've done it myself with RFID stuff I've gotten off ebay for less than $50 bucks. You can do it with the 125KHz stuff and the 13MHz stuff. The range varies a little but well within usable limits. It is true that a lot of it hinges on good antenna design which can make it difficult to hide the thing.... well, not really. Anybody who can hide a Kadee uncoupling magnet can hide an RFID reader antenna... IMO :-)
jwhittenNo way-- you can go an easy 8 to 15 inches with el-cheapo off-the-shelf stuff. I've done it myself with RFID stuff I've gotten off ebay for less than $50 bucks...
. We looked in to RFID tags on the bottom of each piece of rolling stock in the club so the dispatcher could tell the exact location of every piece of rolling stock and locomotive at any given time. Yup just like the prototypes do except instead of being located on the sides of each car we were going to place a tag underneath.and have readers placed in strategic places around the layout. That idea went south when we calculated the cost involved.plus there did seem to be other issues such as others have mentioned but it's a growing technology so who knows whats on the market now.
So we use plan A: magnets on a board. The kind you can slip a little piece of paper into with the road number or car number. There are two per piece or rolling stock and locomotive. When a locomotive is in a particular yard or siding or the Round house the corresponding magnet is placed on the track diagram. The dispatcher does the same thing on is board with the aid of an assistant dispatcher. So at any given time during operations when there can be up to 40 trains running if you want to know where car ABC123 is you check with the dispatcher and if it's not where he says it is then someone dropped the ball. It usually isn't too hard to find out who the guilty party is. Even during a work session or any other time if there is a trouble ticket as well call it for a car or locomotive that may have ad some issues during the last op session the repair crew can go to the dispatchers board and find exactly where that piece is. With several thousand pieces of rolling stock and I think we are some where around 140 operational locomotives this system is an absolute must.
Here's a crazy idea:
Turn your roundhouse into a giant multiplexed programming track.
You'd have a dpqt switch that toggles between track power and programming track for all the tracks around the turn table. The track power on the table itself will shut off when in programming mode to prevent "accidents".
The tricky part is creating a computer controlled set of relays (the mux) that would supply programming track power one track, read back the CV(s) for the loco number, and then show that on the board above the corresponding stall. You could create a script that would cycle through each of the stalls on startup and each time the switched is flipped from run to programming.
This entire thread reminds me of the NASA zero G ball point pen story.
Dave
Lackawanna Route of the Phoebe Snow
Phoebe VetThis entire thread reminds me of the NASA zero G ball point pen story.
CSX RobertPhoebe Vet This entire thread reminds me of the NASA zero G ball point pen story. How?
Phoebe Vet This entire thread reminds me of the NASA zero G ball point pen story.
Early in the space program NASA discovered that ball point pens need gravity to work and so could not be used in orbit. They spent more than a million dollars developing a pen that would write in zero G.
The Russians used a pencil.
I would hang a small whiteboard on the wall and just write down the address of the engines that are parked in the roundhouse.
Phoebe VetEarly in the space program NASA discovered that ball point pens need gravity to work and so could not be used in orbit. They spent more than a million dollars developing a pen that would write in zero G. The Russians used a pencil.