[asterisk-users] GEN-GEN and Manual Ring-Down (MRD)?

Tilghman Lesher tilghman at mail.jeffandtilghman.com
Mon Nov 10 15:34:38 CST 2008

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.)


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