[Asterisk-Dev] TDM400P FXS polarity reversal / coin control

[Strom Carlson]

Hello,

I originally posted this to Asterisk-Users, but since the thread seems
to have died there, I'll quote the relevant bits of the discussion,
because I would really like to see these features implemented :)

I have two coin telephones that I would like to run off my Asterisk
box.  The first is a modern smart phone which handles all coin control
functions internally, but relies on a talk battery polarity reversal
to indicate call supervision.  At this point. there doesn't seem to be
a way to do that with Asterisk, although the hardware looks like it
should be able to handle it:

> Specs for Si3210 (TDM400P FXS Module) says on page 93:
> 
> ---
> Register 72. On-Hook Line Voltage
> 
> Bit 6 VSGN On-Hook Line Voltage.
> The value written to this bit sets the on-hook line voltage polarity
> (VTIP–VRING).
>  0 = VTIP–VRING is positive
>  1 = VTIP–VRING is negative
> ---
> 
> I wonder if this can control Pol-Rev's.. ?  


The second coin phone is an older single-slot electromechanical phone
which does not rely on polarity reversal for call supervision but
which does require +130vDC or -130vDC for coin collect and return. 
bkw claims that the TDM400P FXS module should be able to generate
this, but isn't sure.

I know, this is all a pipe dream, but it would certainly be fun to get
my coin phones working :)

-- 
Strom Carlson
http://www.stromcarlson.com/