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#205822 - 04/08/12 11:07 PM RJ-31X  
Merlin  Offline
Member
Joined: Jan 2004
Posts: 170
NW Indiana
I rrecently finished a new home that I installed all electrical, cat5e, and RG-6U. I always terminate all voice and video circuits in a siemens network panel with the appropriate hubs.

This particular home also has an alarm system installed by another contractor. I ran a cat5e from the alarm panel to the network panel. The master hub that I use as an RJ-31X port built into it. My understanding is that if the alarm patch cord is plugged into it, that it "breaks" the incoming telco circuit and routes through alarm contacts. And that once that patch cord is unplugged from the RJ-31X port, that the circuit goes back to normal. This one does not seem to work that way. If I unplug alarm patch cord, I must jumper the RJ-31X port and the expansion port to get a tone.

Am I correct in my assumptions? Also, what is the "proper" configuration for this type of set-up? The alarm installer has never seen a this type of configuration and appears confused as well.


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#205823 - 04/09/12 02:32 AM Re: RJ-31X [Re: Merlin]  
LarryC  Offline
Member
Joined: Jul 2004
Posts: 783
Winchester, NH, US
Are you wired correctly? Ring & Tip go to the phone company, and R1 and T1 go to the house phones.

http://www.hometech.com/kb/questions.php?questionid=78

Larry


#205826 - 04/09/12 09:37 AM Re: RJ-31X [Re: Merlin]  
Merlin  Offline
Member
Joined: Jan 2004
Posts: 170
NW Indiana
Yes, I understand the alarm configuration. But the network hub with the RJ-31X port is the problem area. It is my understanding that when I unplug the RJ-45 connector that goes to alarm panel, from that port, that the hub should return to normal state. That is not the case. Am I doing something wrong or do I have a bad master hub?

Also, what is the proper configuration of the RJ-45 that plugs into the RJ-31X port? 568A?? And, which pair would then land on T1 - R1?


#205828 - 04/09/12 01:11 PM Re: RJ-31X [Re: Merlin]  
LarryC  Offline
Member
Joined: Jul 2004
Posts: 783
Winchester, NH, US
"Also, what is the proper configuration of the RJ-45 that plugs into the RJ-31X port? 568A?? And, which pair would then land on T1 - R1?"

According to the link I posted, T1 & R1 are pins 1 & 8. These do not match up to any pairs. For 568A they are Green/White and Brown. For 568B they are Orange/White and Brown.

Ring and Tip are pins 4 & 5. They correspond to Blue and Blue/White for both 568A and 568B.


#205829 - 04/09/12 07:53 PM Re: RJ-31X [Re: Merlin]  
Merlin  Offline
Member
Joined: Jan 2004
Posts: 170
NW Indiana
OK. I did see that, however since it didn't correspond with a pair, I thought maybe there was a different configuration for mating with an RJ-31X. Thank you.

I am still confused as to why when I unplug the alarm patch cord from the RJ-31X, that it fails to return to normal state as I think it should.


#205830 - 04/09/12 08:51 PM Re: RJ-31X [Re: Merlin]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,087
Estero,Fl,usa
I Thought I already posted this but if you punched the block to the USOC standard pins 1 and 8 would be the brown pair.

That is an old Telco standard and not used for data.

The pairs fan out like 4-5 and 3-6 all the way to the end
(2-7 & 1-8)

This is the RJ31X

[Linked Image]


Greg Fretwell

#205874 - 04/15/12 05:52 AM Re: RJ-31X [Re: Merlin]  
techie  Offline
Member
Joined: May 2005
Posts: 246
palo alto, ca usa
Originally Posted by Merlin
Yes, I understand the alarm configuration. But the network hub with the RJ-31X port is the problem area. It is my understanding that when I unplug the RJ-45 connector that goes to alarm panel, from that port, that the hub should return to normal state. That is not the case. Am I doing something wrong or do I have a bad master hub?

Also, what is the proper configuration of the RJ-45 that plugs into the RJ-31X port? 568A?? And, which pair would then land on T1 - R1?


A couple of things.

It's not a "RJ-45" plug. It's a 8 position modular plug, wired to a specific standard, which may be RJ-45 (which actually calls for a keyed plug), RJ-48, RJ-61, RJ-31, TIA/EIA-568A or B, etc..

The jack/plug only gains an RJ designation when wired in a specific manner, for a specific telephone application.

Non-telephone applications such as ethernet have never had a RJ designation.

If you actually wire a cable to the RJ-45 spec, it will be neither physically, nor electrically compatible with ethernet.

In this case you are wiring the plug to the RJ-31 standard.

T/R is the incoming line from telco to the alarm panel. T1/R1 is the loop out of the alarm panel to the rest of the phone equipment, which is live until the line is seized by relay in the alarm panel.

Last edited by techie; 04/15/12 05:53 AM.

#206028 - 05/11/12 08:51 PM Re: RJ-31X [Re: Merlin]  
hbiss  Offline
Member
Joined: Dec 2003
Posts: 886
Hawthorne, NY USA
I think your problem is that you are using a structured wiring panel. Learn how to do it yourself with patch panels and you would be able to see your problems.

All security companies that I have ever ran wire for always wanted the RJ-31x either in their panel or next to it. The RJ-31x is also capable of providing a tamper indication to the panel if the plug is removed. The always use a premade alarm cable from the panel to the jack with an 8pos/8pin plug. 568A or B is irrelevant, there are spade lugs on the other end.

Study that drawing that Greg provided. CO Line comes in on pins 4&5 and goes out the the phones on 1&8. When you pull the plug there are shorting jumpers that connect 1 to 4 and 5 to 8.

-Hal



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