I was just given a Digitrax BDL Block Detector and 5 IRDOT ( only # I could find). I run MRC Advance.
My question is can I use this with my system or am I going to have problems? This is my first attempt at this.
Harold
To use the BDL168 you will have to set up a Loconet and interface it with a computer - you do not need to switch your system to Digitrax, nor do you need a Digitrax command station. The Locobuffer-USB interface can act as the Loconet master, and connect Digitrax detection and signalling devices. Several NCE users have done this same thing to get Digitrax signalling and detection. JMRI can address multiple systems at once.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy
From what I am reading you need to do this through a computer and not to my MRC command station. Am I correct? In this case does the computer use an internet connection? As my layouy is located in a metal shed away from the house I do not have internet there.
hwolf I was just given a Digitrax BDL Block Detector and 5 IRDOT ( only # I could find). I run MRC Advance. My question is can I use this with my system or am I going to have problems? This is my first attempt at this. Harold
You don't say how you want to use them.
The IRDOT is an optical detector. It can be a stand-alone item, in that it can detect rolling stock and trigger a state change in a light. As in going from off to on.
Here's an article on one of them:
https://heathcote-electronics.co.uk/irdot1.html
There are different versions.
The Digitrax BDL apparently came in three numbers: 16, 162, 168. The latter being the current model. You may have an earlier model.
Here's the instruction sheet:
http://www.digitrax.com/media/apps/products/detection-signaling/bdl168/documents/BDL168_flattened.pdf
The BDL appears to be a current sensing device. It will detect a locomotive and any rolling stock equipped with a resistor.
Ed
Sorry
It is a 168. How would the two of these work together? What I am really trying to figure out is this worth all the work?
No internet connection is needed - after you get the software ont he machine. But you can download that in the house and use a memoery stick to take it out to the shed. While running, there is no internet connection, JMRI runs and only communicates witht he layout devices, not the internet.
The BDL-168 doesn't have inputs that can handle the IRDOT sensors. The SE8C signal driver does, as do DS64 stationary decoders. Unfortunately there is still some additional hardware needed because the out of the IRDOT is not directly compatible with the inputs on Digitrax devices, or amny others, actually.
hwolf Sorry It is a 168. How would the two of these work together?
It is a 168. How would the two of these work together?
One senses current. The other is optical. I use a current sensor (NCE BD20) and an optical detector (Iowa Scale CKT-IRSENSE) for signaling. The WHY is because each does a different job--using both properly puts together an excellent detection system. The HOW is, well, beyond me. I've used the IRDOT. But I've not used the 168. And there are likely different ways to get them to work together, depending on the design of your entire system.
You don't say what you want to do with these things. As I said, I use similar items in my signaling. I'm gonna assume you want to do the same.
What I am really trying to figure out is this worth all the work? Harold
What I am really trying to figure out is this worth all the work?
Signaling IS a lot of work. Not so much the physical work part, but the mental. It doesn't come easy to most people.
My layout has been complete (never) so I was going to get into signals and or block detection. A member at our club buy layouts and sell them at train shows. He had these two items but has no clue how to use them. So I got it and now I have to figure it out.
It's not too difficult to hook up the BDL-168, it's just rather inconvenient if you already have a power bus around your layout, because it centralizes all 16 detection sections. One side of the bus goes in to the BDL-168, and 16 wires run out under the layout to power each isolated detection section. Connecting wires is much easier with the Acculites Break Out Boards.
Instructions for the IRDOT sensors should be on their web site.
Harold,
That's what I figured, but "ya never know". The IRDOT can be totally stand-alone if all you want is an occupancy sensor for a hidden track.
But SIGNALS!
Well.
First you should learn how they work. The REAL ONES. You can, of course, make something up, if you prefer. But since you're modeling, you might want to also model how the real ones work. So educating yourself in the field is good. It at first looks really complicated. And it sort of is. But after awhile, you see the logic, and you kind of "get it". And things start to fall in place.
Bruce Chubb did an excellent series on the subject in RMC recently. Of course, if you need to buy the whole set of back issues, there's a pretty penny there.
A good way to go is to do searches about the subject. I've found some good sites that way.
You'll also have to figure out how to adapt what you learn from your studies above to your layout. For example, you will now have a good idea where signals should be placed. And what kind, two head or single head, for example. And what to do about switches. And how to select your detection blocks (real railroads have them, too).
There are also several approaches to building a signal system. Signals are, by the way, a system. There's not just one standing there all by itself. They all interact. You quite possibly will want them to interact in a way that recreates the real ones. The new pieces you got for free might very well fit into one or more of these approaches.
I will confess that I do not have a proper catalog of them all. I am only familiar with one (MSS). It works very well for me, so I don't spend much time looking at others. There does seem to be a multitude of these "approaches".
I do think you could learn a lot by entering the word "signal" over in that "Search the Community" box and seeing what comes up. We've kicked signaling concepts around a bit, here.
Good luck,
In designing my ABS signaling system I used the knowledge that I gained from these books:
1. Introduction to North American Railway Signaling (Simmons-Boardman)
2. All About Signals (John Armstrong, Kalmbach)
3. Railroad Signaling (Brian Solomon)
4. Classic Railroad Signals (Brian Solomon)
All were quite useful. I used 10 Dallee Trak-DT detectors for the 5 blocks on the eastward main and the 5 blocks on the westward main. My layout is wired for DC operation. The signals are made by Custom Signal Systems and are the Union Switch & Signal TP-5 type (quite rare). The signal bridges are from Alkem Scale Models. My layout is not large (12 ft x 13 ft) but I wanted to have ABS signaling with a CTC-controlled set of crossovers. The signals are in place and operating flawlessly. I now need to install resistors across the axles of my cars and cabooses so that they are detected in the blocks. The CTC panel (yet-to-be-built) will control the crossovers and kick the top "arms" to red when the lower arms are at a diverging aspect. The other ABS signals should respond correctly. I have worked this all out in my wiring diagrams. Hopefully it will work as designed. Here are some photos:
https://photos.app.goo.gl/nNZybvhhfLom5NgB2
If one uses optical detectors (such as the IRDOT) in co-ordination with current sensors (such as the 168), resistors are not needed on rolling stock.
Or, going in the other direction, if resistors are on rolling stock, then optical detectors are not needed.
I just found out from Digitrax if you go into the Digitrax system ( club uses Digitrax ) you can set up a Master Loco-net which will then allow you to use another system.
For it to be useful, you'll either have to run a digitrax command station ORPurchase a PR3 OR PR4 and run JMRI.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
The circuit is actually very simple for getting block detection to work. When you get current or high voltage (IRDOT) in Block 3, you send power to red signal in Block 2 and power to yellow signal in Block 1.All it takes is a simple transisor attached to current detection loop, or high voltage loop on IRDOT.There are advantages and disadvantages to each approach.
IRDOT - If you have a really short train, once your rear of your train passes the IRDOT the circuit might think the block is empty. There's a couple ways to combat this...1. Put a decent sized capacitor on the input leg of the transistor which will hold the voltage up for a bit and help reduce noise. But it might delay the circuit turning on also. It won't help you if you stop your train in the block either.
2. Put in a lot more IR Sensors
3. Build a latch and release circuit with IRDOTS at the begining and end of each block. When the train enters, an accumulator goes to 1. When the train hits the second IRDOT, the accumulator goes to 2. When the signal goes low and accumulator = 2, reset accumulator to 0. When accumulator != 0, send yellow and red to respective circuits. The disadvantage here if you might confuse the accumulator if you have two trains enter the same block at the same time, or when you power up, the train is already in the block. The block also has to be longer than the longest train, or you have to apply another logic circuit. If IRDOT 1 went high, then wait till IRDOT 2 goes low. If IRDOT2 went high first, then wait till IRDOT 1 goes low.
Method 2
Current sensing. Current sensing works very well because it will work anywhere in the block the train is located. The only disadvantage is you have to have current sensing wheels on the last car in your train. If you have a large fleet, that could get expensive. The most commong technique is to take a 1kOhm SMD resistor and glue it to the axel. Then take conductive paint (available at auto stores for window heating wire elements) and paint a line to each wheel back.Hope this helps
DonNow if you wanted automated stopping of trains for red signals...well things get a bit more complicated.
RR Cir-Kits LocobufferUSB also works.
Many people have done this, no Digitrax command station. Quaker Valley is a fairly large one, NCE to run trains, Digitrax and JMRI for the block detection and signaling.
rrinker RR Cir-Kits LocobufferUSB also works.
Quite true Randy. Probably cheaper too. I just like the PR3/PR4 because you can use it as a programming track too from JMRI. (Without the need of a command station)
DigitalGriffin The circuit is actually very simple for getting block detection to work. When you get current or high voltage (IRDOT) in Block 3, you send power to red signal in Block 2 and power to yellow signal in Block 1.All it takes is a simple transisor attached to current detection loop, or high voltage loop on IRDOT.There are advantages and disadvantages to each approach. IRDOT - If you have a really short train, once your rear of your train passes the IRDOT the circuit might think the block is empty. There's a couple ways to combat this...1. Put a decent sized capacitor on the input leg of the transistor which will hold the voltage up for a bit and help reduce noise. But it might delay the circuit turning on also. It won't help you if you stop your train in the block either. 2. Put in a lot more IR Sensors 3. Build a latch and release circuit with IRDOTS at the begining and end of each block. When the train enters, an accumulator goes to 1. When the train hits the second IRDOT, the accumulator goes to 2. When the signal goes low and accumulator = 2, reset accumulator to 0. When accumulator != 0, send yellow and red to respective circuits. The disadvantage here if you might confuse the accumulator if you have two trains enter the same block at the same time, or when you power up, the train is already in the block. The block also has to be longer than the longest train, or you have to apply another logic circuit. If IRDOT 1 went high, then wait till IRDOT 2 goes low. If IRDOT2 went high first, then wait till IRDOT 1 goes low. Method 2 Current sensing. Current sensing works very well because it will work anywhere in the block the train is located. The only disadvantage is you have to have current sensing wheels on the last car in your train. If you have a large fleet, that could get expensive. The most commong technique is to take a 1kOhm SMD resistor and glue it to the axel. Then take conductive paint (available at auto stores for window heating wire elements) and paint a line to each wheel back.Hope this helps DonNow if you wanted automated stopping of trains for red signals...well things get a bit more complicated.
There is, as I have said, a way to use both current and optical detectors, and negate the problems noted above. Including the need to use resistors on cars.
7j43kThere is, as I have said, a way to use both current and optical detectors, and negate the problems noted above. Including the need to use resistors on cars.
I see what you are getting at. If it has current, the engine has to be in the block. If you have an IR signal at each end, and the engine isn't in the block, then the IR sensors will trip on the rolling stock.That would work well with DCC as long as there is always power to the block.
DigitalGriffin 7j43k There is, as I have said, a way to use both current and optical detectors, and negate the problems noted above. Including the need to use resistors on cars. I see what you are getting at. If it has current, the engine has to be in the block. If you have an IR signal at each end, and the engine isn't in the block, then the IR sensors will trip on the rolling stock.That would work well with DCC as long as there is always power to the block.
7j43k There is, as I have said, a way to use both current and optical detectors, and negate the problems noted above. Including the need to use resistors on cars.
It has worked quite well, in my experience.
If a train were to break, and the locomotive and the rest of the train left the block, the signals for the train-break block would go green. Which wouldn't happen in real life. On a model railroad, people notice that sort of thing quickly. If not the train's engineer, then the engineer of the next approaching train.
All the more reason to have good trackwork and coupler installation.
On a Free-mo layout, which is what I operate on, the trackwork is very simple and mostly out in the open, so it's very easy to be aware of both your train and other trains in the area. Especially the cars that are dead and are 5 feet in front of you.