asterisk users - Nov 2008 - GEN-GEN and Manual Ring-Down (MRD)?

Does anyone here know anything about GEN-GEN analogue circuits, also
known as Manual Ring-Down (MRD)? Apparently they are widely used in
Hoot'n'Holler systems for financial dealer-boards.

I have been asked to try and interface to such circuits, and have been
having great difficulty locating any specifications for the interface.

Apparently, they are always-on 2-wire analogue circuits with no tip
voltage or loop current, and on-demand superimposed ringing voltage in
either direction for signalling (to do nothing more than get the remote
end's attention).

I was wondering whether it is possible to adapt an FXS or FXO port to
operate in such a mode, but I'm not optimistic.

Cheers
Tony
-- 
Tony Mountifield
Work: tony at softins.co.uk - http://www.softins.co.uk
Play: tony at mountifield.org - http://tony.mountifield.org

On Monday 10 November 2008 05:56:18 Tony Mountifield
wrote:
> Does anyone here know anything about GEN-GEN analogue circuits, also
> known as Manual Ring-Down (MRD)? Apparently they are widely used in
> Hoot'n'Holler systems for financial dealer-boards.
>
> I have been asked to try and interface to such circuits, and have been
> having great difficulty locating any specifications for the interface.
>
> Apparently, they are always-on 2-wire analogue circuits with no tip
> voltage or loop current, and on-demand superimposed ringing voltage in
> either direction for signalling (to do nothing more than get the remote
> end's attention).
>
> I was wondering whether it is possible to adapt an FXS or FXO port to
> operate in such a mode, but I'm not optimistic.
That sounds curiously like an FXS in immediate=yes mode (i.e. batman
phone, red-phone, etc.)

-- 
Tilghman

On Mon, Nov 10, 2008 at 6:56 AM, Tony Mountifield
<tony at softins.clara.co.uk> wrote:
> Does anyone here know anything about GEN-GEN analogue circuits, also
> known as Manual Ring-Down (MRD)? Apparently they are widely used in
> Hoot'n'Holler systems for financial dealer-boards.
>
> I have been asked to try and interface to such circuits, and have been
> having great difficulty locating any specifications for the interface.
>
> Apparently, they are always-on 2-wire analogue circuits with no tip
> voltage or loop current, and on-demand superimposed ringing voltage in
> either direction for signalling (to do nothing more than get the remote
> end's attention).
>
> I was wondering whether it is possible to adapt an FXS or FXO port to
> operate in such a mode, but I'm not optimistic.
Your understanding of MRD is correct (these are nailed-up connections
with only ring-gen capability). I've personally not tried this w/
Asterisk FXS/FXO ports but If you can make it work that way pls. let
us know.

--
Raj Jain