Silent Knight - 5207 - Phone Line Faults

We are currently having an issue with our Silent Knight 5207 where we receive the following codes/faults:

dL (Data Lost)

dF (Failed to Report)

L1 (Phone Line #1 Fault)

L2 (Phone Line #2 Fault)

My individual in charge of the facility indicates that in the past, he has contacted the telco and the security vendor, both would come out, perform some kind of work and the faults will go away for a month or so and then come back again. This has happened several times, and in my opinion, seems like we’re not really getting anything fixed.

From my brief look out there at the equipment, I can see we have the appropriate RJ31X jacks installed for both lines right next to the panel and the interconnects run from those to the actual panel. I was hoping that we had a set of punchdowns on the interior of the building so I could validate the phone lines themselves but it looks like we just have the standard network interface box for our junction.

I was reading the manual for this panel and it indicates the panel measures the amount of DC voltage present on the line to detect trouble, not necessarily that there is a dial-tone. I was able to call both of the phone lines so it seems like they are not disconnected and are at least in service.

If the RJ31X jacks are wired correctly, I’m assuming I can unplug the alarm phone interconnect cables and validate the dial tone with the appropriate patch cable to a normal telephone which should be pins 1 (Ring) and 8 (Tip) of the RJ31X connector to pins 1 (Ring) and 2 (Tip) of an RJ11 connector. After that, I figured I would use a voltmeter to check to see if I have the proper line voltage at the junction box / internal RJ31X jacks / panel. ~48 volts when on the hook and between 3-9 volts when off-hook.

Am I going about this the correct way for troubleshooting? Has anyone else dealt with something similar? I was hoping that someone might be able to help point me in the correct direction for troubleshooting this particular issue… while I am an IT guy, usually my time is spent more on the data/software side of things so I’m a bit out of my element.

You’re going in the right direction. And like you said, the panel only normally checks for phone line voltage, not necessarily a physical dial tone. Once a day, the panel will also attempt to call the central station and send a test report to confirm communications. If any of those things go wrong - loss of voltage on the phone line or incomplete communication attempt, you will get your trouble codes. The DL and DF faults are going to happen if the panel attempts to communicate with the central station and the transmission did not go through - this could be due to an interruption during the call or noisy phone line. The L1 and L2 faults are going to happen with a loss of voltage to the phone line.

First thing I would check - are the phone lines wired correctly at the d-mark. The fire alarm panel should be wired as the FIRST device on the phone line, and wired in such a way so that when the panel needs to communicate, it can disconnect all other telephones on that line. The fire alarm panel phones lines should go right to the d-mark. Let’s take your average Cat5 cable, blue/white pair would be line #1 and should land directly on the d-mark ring & tip terminals (feed). These should be the ONLY wires on the terminals! At the panel, the blue/white pair should be on the red & green terminals on the RJ31X. Then the orange/white pair at the d-mark should then connect to the wires feed all the other phones on that line (return). At the panel, the orange/white pair should be on the grey & brown terminals on the RJ31X. Repeat for phone line #2 using green/white as the feed and brown/white as the return. Attached below is a diagram on how this needs to be wired.

Once you’ve confirmed both telephone lines are wired correctly we can proceed from there. Keep in mind some jurisdictions require at least one phone line be dedicated and you may not be “returning” anything to other phones - then only the red & green terminals on the RJ31X would need to be connected.


Also, I would avoid plugging in a standard telephone RJ11 plug into the RJ31X jack - you may damage the jack. If anything, make yourself up a cheater cord - RJ45 plug with wires in pins 4 & 5 to a standard RJ11/14 jack wired to the red and green. Then you could plug a standard line telephone directly into the RJ31X (via your cheater cord) and verify dialtone.

Thank you for the suggestions Lambda, I will see about checking out the wiring as per the diagram and explanation that you provided. A cheater cord might be a good idea and will see about wiring that up to see if I can even get a dial tone.

I’m not sure I’ll be out there today, but I’ll see about making a trip to the location tomorrow to see.

Just some questions cause I’m curious: When the panel sends the test report to the central station the next time or when it gets confirmation that it has a working connection, will the troubles go away automatically? and Is it possible to accidentally call a panel’s dialer “number”, when calling a business that has a fire alarm system? What would happen if this some how occurred?

Usually they will. Just like any other trouble, like a battery or bell trouble, the panel will clear itself once the trouble has gone away - or in this case once the panel successfully communicates. There are a couple of panels that will latch the trouble until it’s reset or acknowledged by the user. Most failure to communicate or phone line troubles will clear themselves in a day. In fact, if the customer calls us with a “failure to communicate” trouble, we have them disconnect the battery for a couple of minutes then reconnect it. When the panel dials out for the low battery, it sees the successful communication and clears the trouble. No service call required!

As far as being able to call the panel and have the panel itself pick up the line - highly unlikely. Some panels do support being able pick up the line and communicate with a remote computer for programming and there is a way to get the panel to pick up, but I shouldn’t post it publicly. Depending on the jurisdiction, the fire alarm panel may not need to be on a dedicated line. So in fact, when you call a business, you may be calling the line that the fire alarm panel is on. But even if you called a phone line connected to a fire alarm panel and you did get it to answer, not much would happen. You’ll hear a couple of beeps from the panel and it would be waiting for a handshake tone from the remote modem before it did anything. And after a couple of seconds of not hearing anything, it would simply hang up. Think of what happens when you manually call a fax machine.

Great call on the cheater cord! I made one and tested it at our main location (not the one with the issue!) and it worked as expected. When I traveled to the remote location, I found a couple items:

  1. The two RJ31X jacks right next to the fire panel did not have a dial tone when I plugged in a regular phone.
  2. The corresponding wires of the 4 & 5 pins on the first jack that should go to the ring and tip in the d-mark were just dangling at the d-mark. Problem #1.
  3. The corresponding wires of the 4 & 5 pins on the second jack that should go to the ring and tip in the d-mark are connected to a ring and tip post in the d-mark that connects to a metal slide/switch/fuse contraption that doesn’t have a dial tone. Problem #2.
  4. We are supposed to have 2 lines coming in to the d-mark, and we look to only have one of those metal slide/switch/fuse things with a dial tone when I plugged in the phone outside to the individual d-mark jacks. Problem #3.

    So, overall, it looks like I would expect the fire panel to be alerting for line faults, because we only have 1 working dial tone at the d-mark AND both of the wires for the RJ31X jacks (4/5 pin) are NOT connected to any ring/tip terminal with service.

    I think that a service call to the telco can get the second dial tone sorted, and if I’m there on site, I can say, I need these particular wires connected to the ring and tip terminals to support the fire panel.

    Thank you for your help with this!

Anytime. I hope it works out in the end for you!

Just be aware most phone technicians (especially from the phone company itself) don’t have a clue on how to properly wire up an RJ31X. I can’t count the number of times I’ve had to go out to a customer and rewire the alarm at the d-mark because the customer call the phone company about noise on the line. And the phone technician was there, saw the “strange” wiring, didn’t understand why it was wired that way, blamed the static on that, and wired it up “correctly”. Which always removed the line seizure. So just double check the wiring with the above diagram after the phone technician leaves!

Just had the telco technician out today and he was very helpful in getting me squared with the panel. It seems like the last individual we had working on the panel actually disconnected the second line and incorrectly wired the first… so my findings with your help were validated!!! Once we got that squared, he ended up wiring up one of the other test jacks in the junction box at the d-mark so I could test both lines more easily in the event of a future issue.

Thank you so much for your help! Consider this a success!!!