by Jeff Fisher
A long time ago, there were no "automatic" security systems as we know them and folks that could afford it just hired security guards. Other folks went without security.
Then came the first electronic security systems. No great genius, that. They didn't need security guards all over the place to watch everything. But there was still a problem. The user still needed at least one security guard to do something when the alarm went off.
One company decided that having one guard at each of their offices all over town was a bit silly, and ran wire to link all their security systems directly to a board in the local central police station. When an alarm went off, a light would light up, a buzzer would sound, and the police would be dispatched. This is where the term "central station" came from. The fact that a person was actually "watching" the security system at all times is where the term "monitoring" came from.
Thus, the first monitoring company was born. A consortium of business each paid a fee to a new business, whose job it was to simply monitor their alarm system and do something when it went off.
Up until fairly recently, monitored security systems were still "hard wired" with a pair of copper wires to the central station. This is a neat, fail-safe setup. Even if the security system (and building) is completely obliterated in an instant, the central station will know something is wrong due to the change on the other end of the wires. For all I know, banks and such are still hardwired.
We take phones for granted, but it wasn't long ago that using the phone lines for monitoring was simply out of the question; not reliable enough. When the alarm went off, it would have to dial up the central station and report the alarm. There were just too many times that a call could not be completed, and that would result in an alarm not being reported. But stringing copper is expensive, and phones have gotten more reliable. The tremendous growth of security systems in residences has forced homeowners to use the regular phone systems for monitoring.
This actually works pretty well except for one thing: People naturally didn't want to put in an extra phone line for the security system, they wanted the new system to use their existing phone line. OK...but what if the phone is off the hook when the alarm goes off? Or what if the burglar knows about this and simply picks up any phone in the house and interferes with the automated call in some manner?
That's easy, right? Just connect the alarm system ahead of all the phones in the house and build in a relay so it can disconnect house-phones and do its thing. Even if there is a call in progress, it can "seize" the line, hang-up, and dial the monitoring company. There's only one minor "interfacing" problem with this approach. It's almost kinda' silly, but it ended up requiring a unique piece of equipment to solve.
You see...in practice, the guy that puts in the phone wiring, and the guy that puts in the security system, are usually two different people, two different companies, and sometimes, two different planets. They could never agree on where the interconnection between the two systems should be, how it should hook up, etc. And when anything went wrong, they would just point fingers at each other. When the phone installer finished, the phones still wouldn't work because the security system wasn't installed so that its relay could short the inside wiring to the CO (company office) line. If there ever was a problem, there was no easy way to tell if it was the security system's fault. Or, worse yet, if the security system failed, it would take down all the inside phones!
So the telephone installer is simply told to "put an RJ31X jack here" and he is supposed to know what that means. Even though the security system isn't plugged in yet, the phones will still work, and he can go home.
When the security installer has the security panel up and ready, he plugs the panel into the RJ31X jack and he's in business. If there's ever any question about whether the panel is interfering with the phone lines, or if the panel fails, the homeowner can quickly unplug the panel from the jack.
Wiring in the ELK RJ31X Jack
Mount this jack within two feet of the alarm panel so the included cable will reach.
The RJSET jack has 8 screw terminals inside the jack housing. This makes it easy to connect the outside and inside lines. Just connect the lines as shown below. The outside and inside lines can come into the jack from within the wall behind the jack, or into either, or both, sides of the jack.
Connect the 2 foot cord to the alarm panel:
- Red to "R" or "Ring" contact. (Ring, from phone company.)
- Green to "T" or "Tip" contact. (Tip, from phone company.)
- Grey to "R1" contact. (Ring, To inside phones)
- Brown to "T1" contact. (Tip, to inside phones)
Plug the 2 foot cord into the RJ31X jack and test.
Here is the complete hookup diagram.
Connecting Your Security System
Now you need to make a cable to connect the security system to the RJ31X jack (if you aren't using the ELK version). I usually use Belden 1242A quad wire for this cable. (most any cable will work fine for this short single-purpose piece but it's helpful if the color codes match up.) You will also need an eight position modular plug and a modular plug crimp tool.
Note that you can use four conductor flat cable instead of the quad wire, but you'll also have to use a different modular plug.
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