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Re: New BT Charges and 1 hour phone calls. How to enforce them


  • To: ukha_d@xxxxxxx
  • Subject: Re: New BT Charges and 1 hour phone calls. How to enforce them
  • From: "patricklidstone" <patrick@xxxxxxx>
  • Date: Thu, 08 May 2003 09:41:33 -0000
  • Mailing-list: list ukha_d@xxxxxxx; contact ukha_d-owner@xxxxxxx
  • Reply-to: ukha_d@xxxxxxx


> 1) If I want to force a hang-up can I fit a couple of relays in the
phone
> line and trigger these to open simulating the phone line having
been
> unplugged? This is for outbound calls only. I say two relays
ignoring the
> bell wire. Is there a better way of doing it?

This will work, so long as you open the relay for long enough (say >
300ms). Too short, and you will end up simulating "Timed Break
Recall", which corresponds to the "R" button on most phones
- you
will get a second dial tone, putting the first call on hold, as if
setting up a 3 way call or using call waiting.

> 2) Since I have a Meteor I might use this to identify the direction
of the
> call. I already have an application connected to the Meteor which
logs all
> the info into a database etc. so listening to the inbound data
might prove
> a problem. The application came with the Meteor so I don't have the
source
> or anything and I expect it doesn't write the log entries till the
call
> ends. Does anyone know if splitting the serial cable and
simultaneously
> connecting the send from the meteor to another serial port input
will
> enable me to listen to the data stream with my own application?

This will work, so long as you preserve the serial port parisitic
power connections to the meteor in your Y-cable. (ie. make the cable
straight through on all pins, and then add a second plug with just
meteor TxD (pin 2 or 3, I don't remember) & ground (pin 5)
connected). And you could then even use the xAP meteor plug in as the
interface point :-)

> 3) If listening to the Meteor proves a problem I can always attach
some
> special balanced BT relays into the phone line which trigger when a
call
> is made or received and work from there. The tricky bit then would
be
> determining the direction of the call, anyone any ideas here?
>
> 4) Finally, is it possible without spending loads of money to have
the
> computer conceptually  'pick up' another handset and give the
warnings as
> though they were another person on the line?

Yes, this is possible. You'd need to build (or buy) a BT line
interface to the sound card, and switch it in using your relay setup.
Simpler still would be superimposing an advisory tone - if your tone
generator is suitably high impedance, you should be able to get away
with doing it without needing relays. EPanorama is a good starting
point for the design of this type of stuff, and I'm pretty sure
Maplin will have a suitable interface available off-the-shelf.

Patrick



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