Reading bar code under moving Model (HO) car

[Gaundyboss]

I would like to scan a barcode on the bottom of a moving HO car.  This will allow a computer to track train progress on a large layout (14' x 204').  This layout is a demonstration layout that is usually watched over by one person.  It is desired to run multiple trains in a script coordinated by a computer.

I thought that rather than re-wiring tracks into blocks with multiple occupancy sensors - all the commonly used ones have limitations - I would scan all the cars as they passed over a reader and if the next reader did not register all the train I would know that there was a problem (Derailment, uncouple, stall) and could alert operator and/or DCC Control to shut down.

 

I haven't been able locate a sensor/reader that would fit under the tracks and be able to read the barcodes.  If anyone knows if this method has been inplemented before or of a sensor like a scanning wand with a .75" read range please let me know. 

Thank-you for your kind consideration and assistance.

 

Dave Moore

(Gaundyboss)

 

 

[WCfan]

Wow, that's a BIG layout.

I guess you could do somthing like stores do. You could get a cheap bar code scanner, and make some bar coad lables. You could put the scanner in a place where no one can notice it  (like in a tunnel, in between a rock cut, etc.) under you tracks. Then attach the bar code lables to the bottom of you cars or locomotives.

[jeffrey-wimberly]

You will need a white light to illuminate the bottom of the cars as they go over the scanner. Many people are of the mistaken idea that the scanner reads the black bars. Uh-uh! The scanner reads the white area between the black lines by the amount of light reflected back to the scanner. White reflects light, black doesn't.

[WCfan]

You will need a white light to illuminate the bottom of the cars as they go over the scanner. Many people are of the mistaken idea that the scanner reads the black bars. Uh-uh! The scanner reads the white area between the black lines by the amount of light reflected back to the scanner. White reflects light, black doesn't.

I knew I should of listened in science class.

[RedGrey62]

There are many hand held scanners that you should be able to disassemble and get the reader from.  They should fit well between the rails anywhere you like.  Scanners do not need to operate in light, many use laser technology and provide their own light source.

http://www.semicron.com/scannertips.html

Now that you started this topic, it would be interesting to see if this could be used similar to real RRs.  Track cars, make up trains, and decide what destination they need to go to.  With the use of computers and DCC it would open up some interesting possibilities.

Rick

[Anonymous]

I used to build retail systems with barcode scanners.  I think the biggest problem you wil have is the scanner itself.  If you use small economical ones, it works by a trigger control to activate the scanner and so you will have to find a way to do that.  Otherwise the more expensive constant-on or controlled by some kind of fuzzy logic ones will cost you considerably more per unit.  And of coure, the bigger the unit, the larger the opening you will need.  Just think about the ones you see in supermarket, that's a pretty big glass surface to have a reliable high speed read.

BTW, wow!  That's a huge layout!  Gives me a headache just to think about the amount of wires involved!  LOL

[WCfan]

There are many hand held scanners that you should be able to disassemble and get the reader from.  They should fit well between the rails anywhere you like.  Scanners do not need to operate in light, many use laser technology and provide their own light source.

http://www.semicron.com/scannertips.html

Now that you started this topic, it would be interesting to see if this could be used similar to real RRs.  Track cars, make up trains, and decide what destination they need to go to.  With the use of computers and DCC it would open up some interesting possibilities.

Rick

They some what do. They have these tower on the side of the right of way. These work almost work just like a barcode scanner.Tthey recieve the info from a plate on the side of a car.

[Beowulf]

All Electronics Corp., www.allelectronics.com, sells bar code reading wands for $5.00 (cat # BCW-2) and $6.50 (cat # BCW-3).  They are about 1/2" diameter by 6" long, perfect for mounting beneath the track pointing up.  From the illustration and from what I've seen used in stiores, most of the diameter is housing.  Only 14" or less would have to be visible between the ties.  The laser light seems to always be red so it would't be as noticible as a white penlight beam shining on car undersides.

Please do keep us posted on your progress!  My operators would rather have printed switch lists than use car cards with pockets for smaller destination cards.  But none of them want to keep track of the necessary information by hand or by keyboarding.

[cacole]

A suggestion, for what it's worth.  Instead of trying to track every car in a train, if you are only concerned with whether or not there has been a derailment you need bar codes only on the engine and last car in the consist.  If the engine passes the scanner and the last car doesn't, something's wrong!

[jeffrey-wimberly]

The local library here has the automatic hand held scanners that use laser light to read the bar codes. They had fits with them because the room lighting wasn't bright enough and finally had to mount a penlight on the scanner so that enough white light hits the bar code. And I bet you wondered why I said there had to be a white light source. Even the big scanners in the super markets won't work without sufficent light. How do I know this? I used to help install them.

[csmincemoyer]

If you're going to make the investment you may want to also look at RFID technology.  We started using this at work and it's not much more expensive than barcode technology.  I would think in the Niagara Region/Rochester area there might be a source that could help you with some more detailed info.

[cheese4432]

^ isn't that a micro chip thingy? But if my memory serves me correctly that stands for Radio Frequency IDenification. The only bad thing about it is that since the battery takes up space and isn't exactly pretty or to scale you'll need to put inside the car and that's not about to happen on flat cars and empty well cars, unless you don't expect anybody to look inside them when they lack container that poses a problem also.

So the barcode idea might be a  better idea unless you don't have any of the cars metioned above and won't get any ever. Then the rfid is an equally good idea. But with the rfid you only need spare batteries and one reciever. With the barcode you need multiple scanners as mentioned earlier with rfid you will be buying batteries.

I think that they will cost the same but one might be more expensive than the the other but then theres the computer programming wich I have no idea about.

All the above is written as well my memory serves me.

[Vail and Southwestern RR]

If one was going to try this I think RFID is the way to go.  There are tint RFID tags, no battery needed.  Expense is another matter, but that is coming down all the time.  Do some googleing.

 

[Gaundyboss]

Thank-you all for your interest.

The layout is at the Medina Railroad Museum.  I thought that the barcode reader idea would be a solution on three levels.

1) We need to inventory all items in the museum - thousands of items - barcode them and enter them into the museum catalouge.

2) We have a hump yard on the layout with 26 tracks and hope to have it working soon. (Have 130 switch motors to wire up first).  The barcode could be used to sort incoming cars and select proper staging track for outgoing trains.

3)Track train progress on the track.  For actual train tracking we would probably only flag engine and last car/caboose.

We already have software to script trains, control blocks for signaling and control engines  The biggest problem for the moment is the scanner - just haven't found the right unit.  Most are way more complicated(expensive) than is necessary.  The wand type is the right level of technology but most are for contact reading.  I may try to hack one and see if I can increase the read distance.  I figgered that I would probably have to change the light source to infared so it would not be seen by visitors looking at the layout.

Again thank-you,

Dave Moore

(Gaundyboss)

 

 

[nfmisso]

Dave;

RFID is the way to go, the tags do NOT have a power source, they are powered by the radio frequency query signal.  This is the same technology put in cats and dogs to identify them, aka "chips".  Do a Google search on RFID.  RFID is used in pallets on automate assembly lines identify the particular model on the pallet, record test data and other purposes.

[CSX Robert]

I would suggest that you forget about the wand type of scanner, the way they operate, I doubt that you could get any distance out of them. Besides that, they do not operate very reliably even when in direct contact with the barcode.

I've delt with the handheld scanners quite a bit at work. They work very reliably and some of them can be set to scan continuously. I can get some prices if you want me to. How do you intend to interface the scanners with the PC? We can get them with an RS-232 (serial) interface or USB. There are advantages to both and what would work best for you might depend on your software and operating system. We can also get small modules that would be a lot easier to mount, but I believe they are quite a bit more expensive.

I will give you this piece of advice. You say most are way more complicated(expensive) than is necessary. I don't know what price range you are looking for, but you don't want to go to cheap for what you are doing. It won't be very useful if the scanner does not scan the car virtually every time.

[eeyore9900]

I definitely agree on the point of wand type scanners not being reliable. Working in

a public library myself, I've used these puppies for quite awhile. The wand type were

absolutely horrible, & like was said above, even with direct contact with the bar code.

We finally got rid of them & got some hand helds which work much better too. Might be

worth some "in motion" experiments when I work the audio visual desk tomorrow!

 It's a good idea though, & definitely worth some thought.

[tohowalk]

Sounds (and looks) like quite the project. There are some photos on the museum website: http://www.railroadmuseum.net/

 

Tom

[cheese4432]

Dave;

RFID is the way to go, the tags do NOT have a power source, they are powered by the radio frequency query signal.  This is the same technology put in cats and dogs to identify them, aka "chips".  Do a Google search on RFID.  RFID is used in pallets on automate assembly lines identify the particular model on the pallet, record test data and other purposes.

Well in that case rfid trumps barcode scanner. But how big are these? are they like a surface mount led?or bigger?

[BATMAN]

Just a suggestion. You might get out dated hand held scanners from courier companies or the post office. They seem to upgrade often. Another thing I came accross in our latest upgrade is the scanner takes a PHOTO of the barcode and transmits that to the computer. How it all works and why the change I don,t know, but the red light that you point at the barcode is now a dot. This new technology might work better for you, especially if you are using acomputer to run that huge layout.

[twcenterprises]

I have a contact (not really a friend, sort of an acquaintance) who works for a company that is doing a new sort of RFID technology.  He said (last I talked to him) his company was beta testing and field testing some new RFID modules.  To make a long, technical explanation short, these tags were supposed to be in the "cents per piece" price rance, and the readers in the "under $100" range, and reader/programmers, no more than $200 or so.  He said the "tags" could be either reprogrammable, or programmed once, then read only afterwards.  The read only one would be good for (his example) in a bridge, you take a concrete sample, do your lab tests on it, and embed the tag in the concrete, then program it (while the concrete cures) with date, time, temp., lab results, etc., etc.  The reprogrammable ones were ideal for nearly anything, automotive suppliers, retail, auto parts, whatever.  I'll check with him (if your interested) to see how small the ID tags can be had.  If they are small enough, it might be worth looking in to.

Brad 

[dehusman]

They some what do. They have these tower on the side of the right of way. These work almost work just like a barcode scanner.Tthey recieve the info from a plate on the side of a car.

Actually no.  They stopped doing that back in the 1970's.

The technology they use now is RFID chips attached to the car or container that are read by a transponder.  Doesn't need to "see" the car at all.

Dave H.

[dehusman]

For model railroad purposes you don't need a programable chip, just a regular "dumb" chip with just an inventory number will do.  all the car data can be stored in a program external to the chip (like the program you use to actually do something with the info.)

The problem with scanners is that at the lowest level all they give you is a timestamp that a car was at a certain place at a certain time.  To make decisions you actually need another piece of information, what direction was the car going.  By knowing the direction you can automate some decision information.  The problem on a model railroad is is there enough time between when the scanner passes a reader and when the train has to do something to read the cars, make the manipulations and then create some form of output that the operator can use?

Dave H.

[CSX Robert]

You will need a white light to illuminate the bottom of the cars as they go over the scanner. Many people are of the mistaken idea that the scanner reads the black bars. Uh-uh! The scanner reads the white area between the black lines by the amount of light reflected back to the scanner. White reflects light, black doesn't.

I thought the hand scanners we used would work in the dark, but I did not say anything about this in my previous post becasue I wanted to test it and make sure. When I got in to work today, I tested them and they will work in the dark.

Here is one of the suppliers we have delt with:
http://www.posguys.com/

[Beowulf]

Nfmisso reminded us that RFID is small enough to inplant in pets.  I had only thought of the larger E-Z Pass units that stick to our car windshields and the even larger ones on prototype railroad cars.  These tiny RFID units would be the way to go as they wouldn't require a flat area on the car underside.  RFID would also allow great flexibility in locating the reader.

[reklein]

How about no scanner system at all. This won't solve your inventory problem but might solve the operation problem. My suggestion is to use a Hall effect system. A magnet on the loco and the last car in the train is detected by a sensor under the track. If the last car is not detected wire the train to shut off automatically. Should work something like the automatic grade crossing detectors on the prototype. You could still have a barcode for inventory.

[ericboone]

I believe you can get RFID labels that are about as thick and about the same size as a small barcode label.  In volume, they are very cheap.  Because as previously stated, RFID or bar code scanning only tells you when a car is at a particular scanner, it has limitations.

I plan on wiring my layout to use the NMRA bi-directional communications protocol or Digitrax transponding.  (I haven't decided which yet.  The bi-directional is the standard, but is very new and immature while transponding has been around for a while now.)  Then, when the chips get smaller (axle mounted maybe) and cheaper, I hope to equip every car with one so I know were every car on the layout is located.  Then, I could scan the entire layout between operating sessions to get an updated location for every car to somehow dump into a Ship It or Rail Op type program.

[steemtrayn]

Six years, eh? I wonder if they figured it out by now.

[Redore]

RFID is what the real railroads use too.  They have a tag about 2 inches by 6 inches rivited or welded to both sides of the car.

 

nfmisso

Dave;

RFID is the way to go, the tags do NOT have a power source, they are powered by the radio frequency query signal.  This is the same technology put in cats and dogs to identify them, aka "chips".  Do a Google search on RFID.  RFID is used in pallets on automate assembly lines identify the particular model on the pallet, record test data and other purposes.

[betamax]

There is a yahoo group about RFID applications for model railroading, pretty quiet as there is not a lot happening. But people are working on using this technology.

You can get tags that are about the size of a grain of rice, which can be mounted on a truck frame and read by a sensor under the track.  The data can be sent to an application that can use it.  You could even use it to keep track of your locomotives and link them to a database with all the important details...