Infrared Fencing and Security Systems

[ccurzio]

Hey everyone. Since I know there are a lot of DIYers on this forum I thought I'd see if anyone wouldn't mind me picking their brain a bit on this subject.

For many years now, I have been developing a smart home system. I've written the thing myself from scratch, and while it started out a long time ago quite humble - a single motion sensor that would send a message to my pager when it tripped - it has evolved into a super intelligent home control and monitoring system. It does everything from controlling lights (every day it calculates sunrise and sunset times and turns on/off my exterior lights accordingly), controlling my garage doors, sensing motion throughout the house as well as door/window open/close state changes, air particle detection and counting, radiation level sensing, HVAC filter replacement monitoring, and a whole host of other things I can't think of at the moment.

It's taken many years to get to the point where it is now, mostly because I wrote it all myself in my spare time. I know there are many off-the-shelf systems that do a lot of this stuff, but none of them are integrated as one system and none of them can be customized to the level where I can change or add to the source code myself. I always prefer developing my own solutions versus buying someone else's whenever possible. Now as some of you know, I bought a new house last year. My old house was a single-story ranch-style house so it was relatively easy to wire up the motion sensors in the house running all of the wires through the attic. My new house however is two floors, so it took a bit more work to get the motion sensors back up and running in this place.

That's all good to go, but now I'm looking to expand security a bit. Specifically, I want to create "perimeter" security along the outer boundaries of my back yard using infrared beam detectors. A few months ago someone was seen walking across my back yard at around 2 in the morning, and it wasn't me. I had been toying with the idea of perimeter security well before that happened, but that was a pretty good motivator to ramp up my efforts. Last week I rewired a bunch of stuff in my house's crawlspace and I installed a very nice 500W industrial floodlight pointed at my back yard. The goal is to have a system that will generate infrared beams along the perimeter of the yard and if one of the beams is broken, the incident is logged in my system and the floodlight comes on.

I can handle writing the software that will control the light and read the input from the sensors, and I know and own the hardware required to control the floodlight, it's the infrared system that's giving me a little bit of trouble. So I'm wondering if anyone here has any experience with IR beam detectors.

I'm looking at buying these: http://www.optexamerica.com/security-products/ax-100tf

Thing is, there isn't a whole lot of good information on how those work. At first glance it looks like the system is sold as a pair, but upon reading further it looks like you're buying a single unit requiring the purchase of a companion unit. Problem is, I can't figure out where to find the companion unit. They make wireless models as well, but there's just so little information on what's required at the receiving end and I can't figure out where to go from here.

Does anyone have any experience building such a setup that can offer me some advice?

[Bitsyncmaster]

Do you plan to run wires to those emitters and detectors? They would be pretty high power so batteries would not last long. Motion detectors may work better.

[ccurzio]

Do you plan to run wires to those emitters and detectors? They would be pretty high power so batteries would not last long. Motion detectors may work better.

Since the beam detectors are contact-closure they need to have wires run anyway, so yes.

[David T]

Since the beam detectors are contact-closure they need to have wires run anyway, so yes.

You might want to step up another level and try video. You can do analog which is cheaper or you can go with IP. Then there is color and infra-red. You can set up the camera for motion detection, record and alarm. You can view remotely over the internet. You can get PTZ (pan, tilt,zoom). If you do beam you have to figure you will get a lot of nuisance trips from wildlife. You can discriminate better with video.

[Dangermouse]

Don't know what your budget is, but these work well for machine safety applications.

http://www.bannerengineering.com/en-...rtain-Systems/

IR beam over the height of the post.


Failing that, contact your nearest Bond villain to see what he uses to protect his stolen art work, but isn't activated by his fluffy white cat.

[ccurzio]

You might want to step up another level and try video.

Video is going to be a separate project entirely. Right now I'm focused on active perimeter monitoring and passive motion detection.

Don't know what your budget is, but these work well for machine safety applications.

I came across them while I was doing research for the project. Good equipment, but the range can't even pretend to meet my needs.

[Dangermouse]

[QUOTE=Accipiter;134271
I came across them while I was doing research for the project. Good equipment, but the range can't even pretend to meet my needs.[/QUOTE]

70m isn't enough? You can daisy-chain them too.

"Systems have ranges up to 70 m, with power and range for all types of applications including long-range perimeter guarding".

[ccurzio]

70m isn't enough? You can daisy-chain them too.

Well yeah, that'd be more than enough. I was referring to the light machine safety versions. (cardboard-box width as pictured.)

The application itself isn't really what I'm looking for. Those are indoor safety things from what I can tell, and I don't think they're at all weatherized. Finger detection also isn't really what I'm looking for, so the resolution of these things is way overkill.

[Dangermouse]

True, they are hi-res for their application (safety devices tend to be). We use them for detecting when a person walks through an opening (on a palletizer) that he shouldn't walk through when a machine is running, but they also work when he sticks his hand/arm through.

Btw, they are actually IP65 or 67 rated, so good for outdoors too.

But probably not what you are looking for.


What sort of area are you looking to monitor?

[Notifier]

I started out in 2000 installing security systems but have branched out into fire alarm systems about 8 years ago, so some of my advise may be a little dated but hopefully still relevant. I've installed a few of these types of systems over the years, the one big project we did was to protect a pair of boat yards from people wondering in and fooling around. I also have a set of beams across my garage door to monitor for anyone sneaking in when I have the door open, and a set of beams in my shed for intrusion purposes (not an ideal environment for infrared motion detection) .

Optex is one of the best brands in my opinion, and is the only brand I've even dealt with. I'm not sure where you are looking but I have always known these units to be sold in pairs - a transmitter and receiver in the same box. I'm not sure what you mean by a "companion" unit. But they work basically on the idea of an infrared beam, think TV remote control, but in a really focused beam. They are really easy to set up. There is a built in scope on the device that allows you to see the other one, then you fine tune things with a multimeter. It is very important to mount them to a post, wall, or fence that will not move, because any break in the beam would set off the alarm. We would use metal fence posts set in concrete. This would allow us to run the wiring inside the post and come out underground or in conduit. I would go wired, forget wireless. Too many headaches with switching out batteries, signal strengths, etc. For underground wiring you can use direct burial telephone wire (really tough stuff, what they use from the street to your house, gel filled with shield) or irrigation wire. I wouldn't use cat5, a little too thin gauge in my opinion. You will need to feed 12volts to the transmitter, and 12volts plus your "zone" to the receiver, so 4 conductor cable is what you need. There are also connections for tampers (if someone were to pull the cover off) and I believe contacts to tell you when fog or rain have obstructed the signal. Hook them up under your own discretion - sometimes they cause more problems then they are worth.