[Gllug] Autodiallers with “Line Sensing”

Tim Porter tim at timporter.co.uk
Wed Jun 25 00:17:02 UTC 2008

Someone already mentioned SMSing, that sounds like the best way to go. I
have a system in place using the clickatell.com api, not free but very
cheap per message. Their services are more geared towards sending bulk SMS
(not spam of course), but they are more than adequate for the occasional
message. I am monitoring a few bits of software/system status such as load
and the like. A power cut sensed by the UPS will send me a text and various
other load limits etc, to safisfy my worries it also sends me an "all ok"
message every 8 hours which I normally ignore but is good to know that
things are working and the system hasnt gone down. I have been recieveing
them for so long that I can only assume I would notice if one failed to
come through but thats never happened so I dont know.

All the data that I need to have monitored by this system i can get from
the command line and hence a little cron script, the UPS automatically
fires up certain other scripts depending what has happened to it but the
rest is via crons. I dont know about you floor water sensors but if you can
get their status from the command line you should be able to implement

Tim P

On Fri, 20 Jun 2008 18:46:52 +0100 (GMT Standard Time), Richard Westlake
<r.westlake at mail.cryst.bbk.ac.uk> wrote:
> Hi
> Has anyone used or know of any Alarm Diallers or Autodiallers which have
> “Line Sensing” function.
> By “line Sensing” I meant that it continually monitor the telephone
> line
> and if the line is disconnected or has some other problem then the device
> exerts a digital output e.g. closes some relay contracts.
> We would like to install an environmental monitoring system to warn of
> critical conditions in a server room. For example:
> *)  room temperature to high
> *) under floor water rope sensors have detected a leak
> *) Volt free critical alarms from the air conditioning units
> I was hoping that the monitoring system could trigger an autodialler
> would then call the buildings main reception, which  is staffed 24x7,
> could the pass on the message to the appropriate people, usually the
> estates and facilities department. At present the institution for sending
> this like of alert is a voice call to reception or a rather expensive
> connection to the Building management System (trend)
> I am concerned that as critical alerts should be very rare a problem with
> the autodialer or its phone line could go undiscovered for a long time.
> A solution would be to have the autodialer actively exert a digital
> to indicate that it was operating normally and exert a second output to
> indicate that the line was OK. Alternatively it could just exert one
> output to indicate that everything was working normally and the telephone
> line was OK. The monitoring system could also check these digital outputs
> and notify the IT team by email or some other method.
> This would be a problem for the IT team rather then Estates and
> Facilities.
> I would prefer it to actively exert the output e.g. close relay contacts
> which are normally open as this provides “fail to safety”. If the
> power
> failed, the monitor cable was disconnected or the unit developed a fault
> then we would get a notification.
> I release that there is the risk of an “out of hours” critical alert
> and
> telephone line failure occurring at the same time, given the rarity of
> each individual event this is somthign we ca probably live with.
> All the best
> Richard Westlake
> ----------------------------------------------------------------------
>                 Truth endures but spelling changes   

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