[Asterisk-Dev] Raising loop current limit on the Proslic (reg.71)

[Matteo Brancaleoni]

Hi all.

today I experienced a weird problem with a tdm400,
since the card was working ok with analog
phones, but as soon as I connected it
to a pbx, I started having strange behaviour
on the modules, resulting in lots of power alarm
and module resets.

So after digging into the pbx analog interface
tech spec, I thought that perhaps the loop
curruent provided by the card wasn't sufficient.

Not having tech specs of the tdm400 , I got
the proslic datasheet, and found that registry
71 permits to set the ILIM (max allowed loop current).
But the wcfxs module doesn't set it, so
the value is at the default value 0x00, is to say 20 mA.
Since a standard analog line is at least 30 mA,
I raised that value to 0x07 (41 mA) with wxfxs_setreg(wc,card,71,0x07).

After that, all started working okie and no more power alarms.

Now, there's a pratical reason to not set that
maximum allowed loop current and thus limiting it to
20 mA ? Since that is a max value, and not
a continuos value, I think that shouldn't be a problem,
but... perhaps I'm wrong?

I think that could fix also some issues found with
modules resetting for a power alarm... 

If is ok, I'll send a patch to bugs.digium.com
with the fix to wcfxs.c

matteo
-- 
Matteo Brancaleoni
Espia System Administrator
Email : mbrancaleoni at espia.it
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