Infrared Fencing and Security Systems

[Lou and "Boo"]

What about something like this in the driveway?

http://www.hkvstar.com/product-news/...ming-pool.html


I dunno just popped into mind.

[ccurzio]

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.

The companion unit I mean would be the second unit. This is what I mean: http://www.smarthome.com/76409/Optex...t-Range/p.aspx

On that page, it says "For a sensor unit to go with the AX-100Plus, please see the Optex AX-100TF." And then when you go to that second page, it says "For a beam unit to go with the AX-100TF, please see the Optex AX-100Plus.", linking you back to the first one. It really seems as if they're sold separately.

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.

I already have a good idea of how the units themselves work (the IR part of it), but I was not looking forward to trenching for the wires and was considering wireless. Thank you for dissuading me on that point, as well as recommending the direct-bury telephone wire. Amazon has 500 feet of it for around $50, which would be absolutely perfect for me.

This is good info. Thank you so much.

[David T]

The companion unit I mean would be the second unit. This is what I mean: http://www.smarthome.com/76409/Optex...t-Range/p.aspx

On that page, it says "For a sensor unit to go with the AX-100Plus, please see the Optex AX-100TF." And then when you go to that second page, it says "For a beam unit to go with the AX-100TF, please see the Optex AX-100Plus.", linking you back to the first one. It really seems as if they're sold separately.



I already have a good idea of how the units themselves work (the IR part of it), but I was not looking forward to trenching for the wires and was considering wireless. Thank you for dissuading me on that point, as well as recommending the direct-bury telephone wire. Amazon has 500 feet of it for around $50, which would be absolutely perfect for me.

This is good info. Thank you so much.

I don't like the direct burial wire. Too easy to damage it and impossible to upgrade it. Cheap plastic pipe is a better way to go because if the wire goes bad or technology changes you can easily replace the wire and it is more protected inside the pipe. You may also decide to add cameras and maybe you can use the pipe and not have to dig the yard up. Again I suggest you look at cameras for motion detection. They are much more versatile and the money you are going to spend on beam protection can be put towards the cameras now. Not only can they detect motion, they can give you a record of exactly what was detected. BTW, as long as you are digging up the yard maybe you also want to consider leaving a wire for an "invisible fence" for a pet.

[Dangermouse]

Infrared Fencing:

[ccurzio]

I will NOT be using video for motion sensing. I will eventually be implementing cameras all over my property and they will be recording continuously, but again, that is going to be a separate project.

I am not opposed to the pipe idea for the cables, though the path of least resistance will be the path for me. If I have to dig a trench for a wire anyway, if I can just plop it in there and avoid having to run it through a series of pipes on top of it, that will be easier. Since nearly all security sensors are 12v powered contact-closure systems, upgrading would be pretty much a non-issue for the buried cable.

I'm of the "set it and forget it" mentality. I write code that works and works well, and I don't upgrade hardware for the sake of upgrading. I plan to have this system for a really long time, so constantly swapping out hardware isn't on my radar at all.

[David T]

I will NOT be using video for motion sensing. I will eventually be implementing cameras all over my property and they will be recording continuously, but again, that is going to be a separate project.

I am not opposed to the pipe idea for the cables, though the path of least resistance will be the path for me. If I have to dig a trench for a wire anyway, if I can just plop it in there and avoid having to run it through a series of pipes on top of it, that will be easier. Since nearly all security sensors are 12v powered contact-closure systems, upgrading would be pretty much a non-issue for the buried cable.

I'm of the "set it and forget it" mentality. I write code that works and works well, and I don't upgrade hardware for the sake of upgrading. I plan to have this system for a really long time, so constantly swapping out hardware isn't on my radar at all.

I understand where you are coming from. In the security world everything was (and for the most part still is) twisted pair. The industry is moving to CAT 5 IP powered cabling. To try to future-proof your work the best thing you can do is use pipe so when you do decide to upgrade at least you do not have to get a shovel! There is also the inevitable problems from aerating the lawn, digging a mailbox post, lawn sprinkler, etc and for sure it will happen right where your cable is! I also was not a believer in using cameras for motion detection. With the stuff you can buy today it is just programming and you can have the recorder output a dry-contact to your alarm system or even e-mail you. Or you can jury-rig a PC to do it. I prefer a dedicated video recorder but you're a programmer so you might want to do it with a PC. As for not wanting to upgrade your hardware, no matter what you buy, in 5 years when you have a problem with it, it will be easier and cheaper to replace it, especially if it is outdoors. When going outdoors with an alarm system the biggest concern is false (nuisance) alarms. If it is not reliable you will wind up disconnecting it or ignoring it. Most of the better outdoor installations will use a 2 sensor system, ie, you use 2 different sensing technologies and both have to sense an intrusion to send an alarm. Cuts down on the # of falses

[Notifier]

I believe the Smarthome web site is confusing, or at the very least misleading. You should not need to buy both. There are two Optex units, the AX-100PLUS and the AX-100TF. Both units should be packaged with a transmitter and receiver. The AX-100PLUS is a basic no frills unit. The AX-100TF adds two features: Selectable beam frequency and environmental disqualification. "Selectable beam frequency" allows you to stack units on a pole for a greater curtain of coverage. You would put the top set of beams on "channel 1" and the bottom set of beams on "channel 3" to avoid interference. "Environmental disqualification" would allow you to monitor for when the beam was blocked by fog or rain. If your concern is people walking through your yard, the AX-100PLUS should be fine. Someone could crawl under the beam and avoid detection, if they knew the system was there, so if that is a concern go with the AX-100TF and stack them on a pole - one unit about 2' off the ground, the second 4' off the ground. Here are links to both manuals, they also provide some good installation tips:

AX-100PLUS (also covers the AX-100ALPHA - a 4-channel version)
http://www.optex-europe.com/cms/docu..._ALPHA.pdf.pdf
For some reason, the AX-100PLUS is only on the Optex Europe site, I did not see it on the US site.

AX-100TF
http://www.optexamerica.com/sites/de...F%20Manual.pdf

Trenching for wire really isn't that difficult. Low voltage you can get away with just few inches deep. You can even use a lawn edger to make a slit in the dirt to tuck the wire into. If you are worried about damaging the cable, you can protect the cable in some 1/2" plastic conduit (and use conduit found in the electrical aisle, not PVC pipe from the plumbing aisle) but may want to rent a Ditch-Witch for a long run. Or just keep good track of where you run it and avoid things like aerators, mailboxes, kids with shovels, etc.

If you are going to put in conduit for "future use" - go at least 1" and limit your bends. Two 90 degree elbows are about all you will get away with and put in a pull string. All that will make things a lot easier to pull wire through the conduit.

And if you go with the wired version, seal up any holes you make in the unit with a good quality sealant. Spiders love to call these things home. Sealing them up won't keep them out totally, but just limit how bad they take over. Just plan on doing at least a yearly cleaning of them to keep the system up in good working condition.

[ccurzio]

Good call. The first of two shipments has arrived (I bought both the PLUS and the TF), and two devices were in the package - a transmitter and a receiver. I have no idea what kind of crack the people at Smarthome are smoking, but it's either really cheap or really good.

I got a quote from my lawn guy on what he would charge to run the cable for me, and his number is a little too high for my liking so I'll probably end up running the cable myself. The wire is cheap enough that I will skip running it through a conduit and just direct-bury it with an edger. The time-consuming part is going to be wiring up a junction box with a bank of RJ-11 ports to distribute the contact-closure connections and 12v power. That, and figuring out if I want one or two ingress points for the wire to enter the area where the receiving hardware will reside.

[David T]

Try to keep your junction boxes as sealed up tight as you can. Not only for moisture but for bugs. I still think you should consider pipe. Moles, gophers, and other assorted rodents LOVE to chew up wires. When you run stuff outside you need to make it much sturdier than you think otherwise it becomes a maintenance headache. With an edger you can only bury the wire a couple of inches at the most. A better way is with an edging shovel and take out a wedge-shaped chunk of grass and dirt. That way you can replace it and not ruin the lawn.

[ccurzio]

The problem with pipe is that I would need around three hundred feet of it. That raises costs significantly.

The junction box will be "inside", but it will definitely be sealed up quite well anyway.

I also don't have a lawn to ruin. The yard at my place is (currently) shit.