Peter Cousens wrote:
>
> : Cassie Carstens wrote:
> >
> > > >  Does anybody have some specs or pointers to Telephone Pulse Dialing
> > > > protoc. Pulse timing, interdigit times and so on.
> > > >
> > > >> Mark is 33.3ms, space is 66.6 ms
> > > >> You will find it fairly international.
> > > >>
> > >
> > > Anyone have the min. interdigit time
> > >
> > > Peter Cousens
> >
> > After posting the original question, I looked for more info and is
> > also interested in the min/max digit pulse and of course the
> > interdigit times. It is very simple to get a pic to do pulse dialing
> > and most of the newer exchanges can handle pulse dialing. I read that
> > the modern PABX/ exchange can also handle a much higher pulse rate
> > (bit rate ?) so that the waiting to get connected is about the same
> > as tone dialing. Where is the specs ???
> >
> > Kind regards
> > Cassie
>
> I'm making a pulse reader so the min. interdigit time is important to me
> (anyone done this before or know of any sites)
> I assume it would be around 500ms for a modern push button phone
> but what's the minimum I can expect ?
> --
> Peter Cousens
> email: peter@cousens.her.forthnet.gr  phone: + 3081 324450, 380534
> snailmail:  Folia, Agia Fotini, Karteros, Heraklion  Crete, Greece.
Yes. We do pulse dial detection, unfortunately on z8s (unfortunate in
more ways than one) and not at line level which makes life very tough.

Every push button phone we have here gives 33:66 timing. So to detect
pulse dialled digits we start a timer on each make/break event, record
pulses if the timer doesn't time out before the next event and record a
digit if the timer goes on for 100ms or so. I can't recall the exact
inter digit times but it doesn't really matter. Just have a timeout
significantly longer than the 66ms. I've got some Excel sheets somewhere
with lots of pulse dialled numbers on them but I can't lay my hands on
them right now. Let me know if you want a look and I'll dig them out.
I'm sure they're not that confidential to our business.

Rotary dial phones would have to have an inter digit time at least equal
to a dialled '1' unless the dial is forced back to the stop. And if some
silly beggar is playing that game they can't expect their numbers to be
dialled properly

We've played about with lots of tolerances on the timings with little
conclusion. I think we use +/- 7ms or so on the make/break times.

I'm sure Mitel do a chip for pulse dial detection, I'll try to find the
data sheet.

        - Chris