atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems Can you monitor a loop start line for outage

Is there a way to monitor a residential line to detect when there is a service outage, ideally closing a contact on a relay. The 5ESS CO lines terminate in a 1A2 system. We have had several outages, usually from cable cuts, and we only notice the out of service when we try to make a call or have not received any for a while. Thanks in advance for the advice. I'd like to light the Hold button to show a loss of service.

There used to be a device, actually used by alarm companies, that would take the line off-hook every few minutes and if no dial tone was detected would activate some contacts. I believe they have been prohibited because they tie up CO resources.

If your outages are the result of cut cables then all you have to monitor is battery on the line.

-Hal

The line in use LED on my old AT&T 962 and Lucent 930 & 965 telephones will turn on when a telephone line loses battery. If current at&t branded corded telephones behave the same way, and a single telephone located in a strategic location is acceptable, that may be a "quick fix" option to monitor the main (or main & first hunt) line(s)

Here is what I use:

The 962 phone set with the LED turning on when the line is dead sounds like a good option. I'm thinking I can rig up a relay to the LED contacts which would control the lamp under the Hold key (the Hold lamp is in search of a purpose). Any idea on the relay coil power requirements to operate on such a low voltage? I have a 962 set in storage so I'm going to give that a test. Thanks for the ideas!

Not sure about relays. Try parallel connecting one line of the 962 to a telephone line. Isolate the inside wiring and see if the in use LED turns on as I remember my 962 doing.

I just simulated a line failure to see how the 962 reacts (haven't had one in years as I switched to Verizon FiOS).

At home, line #1 on the 962 is set as the primary line. When I isolated the inside wiring, the green status LED for line #1 went out and the green status LED for line #2 turned on. This would normally happen when line #`1 is in use with the addition of the red "in use" LED glowing and if the phone is programmed to switch to line #2 if line #1 is unavailable.

So, plug in the 962, program the unit to make line #1 primary (which it is out of box), as well as program the phone to switch to line #2 automatically when line #1 is unavailable....isolate the inside wiring and the green LED for line #1 should go out and the green LED for line #2 should turn on. The red line in use LED for line #1 will remain off.

If you are in a place where cut cables occur so often that they have become a big part of your life, I would move to a 2nd world country. If you just want to play around and find a use for the lamp under the hold button, I can't criticize your fetish, since it's a commonly-occurring one among 1A2 aficionados.

A friend, a telephone engineer, was involved a number of years ago in designing a device that periodically (every few minutes, ISTR) took a line off-hook, listened for stutter dial tone, and would light an LED if the stutter was detected, indicating a voice mail message waiting to be answered. If regular dial tone was detected, the device would hang up and not set the LED. The FCC got involved, and their opinion was that the device violated a tariff that prohibits a device from seizing dial tone for any reason other than to initiate a telephone call. There was a lengthy battle, I believe even reaching a court for adjudication on the matter. The result was that the device was declared illegal, then, I think, legal again after petitioning the FCC by interested parties.They are still available online.

A check of FCC decisions yields this interesting tidbit of legalese that describes the 8 restrictions on these devices. The process of getting something approved is called a "waiver request" and in this case, the FCC section is 68.312(i).

"Stutter dial tone detection devices must: (1) perform no periodic testing for stutter dial tone; (2) make an off-hook
stutter dial tone check no more than once after a subscriber completes a call, and complete the check no earlier than 4
seconds and no later than 30 seconds after the subscriber hangs-up; (3) make an off-hook stutter dial tone check after an
unanswered call no more than once and do so within 4 minutes after the call; (4) perform no off-hook stutter dial tone
checks after an unanswered incoming call if the visual message indicator is already lit; (5) take the line off-hook for no
more than 2.1 seconds per stutter dial tone check; (6) synchronize off-hook checks when multiple stutter dial tone
detection and visual signalling devices are attached to the same line so that only one check is made per calling event for
a single line; (7) not block dial tone to a subscriber attempting to initiate a call as an off-hook stutter dial tone detection
check is occurring; and (8) not use more than 8 micro-amps of direct current (DC) from subscriber line loop, except
that the devices may draw loop DC sufficient to make authorized off-hook checks."

A device that checks periodically for battery would not be as useful, since a damaged cable can result in a short circuit or a crossed-battery fault, and some, albeit reduced, voltage might still be present in that situation.

Thanks, Arthur for the background on the stutter dial tone. I've seen caller id boxes that somehow check for this and light a LED, and even some AT&T phones. Since I have a 952 set packed away, I'll try Dexman's suggestion first. If that fails, my backup fetish is to light the Hold button when either gararge door is open - a much simpler circuit! Thanks everyone for the creative solutions!