[App_rpt-users] Debugging COS

Andrew Errington a.errington at lancaster.ac.uk
Sun Feb 12 06:58:35 EST 2012

On Sun, 12 Feb 2012 20:45:55 Jim Whiteside wrote:
> I'm still chipping away at modifying a Startech CM108 USB fob - so far I
> have successfully got PTT and audio out working, but I'm struggling with
> audio in and COS.
> I've been following http://www.qsl.net/k0kn/cm108_mod.html
> Can anyone advise if there's a way to determine from the Asterisk side if
> COS is active or not?
> I've even tried manually taking the CM108 pin 48 to 0v and +5v with the
> iax.conf below, but I can't seem to make anything 'happen'.
> My theory was, as soon as I have COS triggering Asterisk correctly, then I
> can look at getting the audio in working properly.

Assuming COS is connected to the Volume Down pin on the CM108 then how about 
plugging the fob into another PC which is not running the Asterisk drivers 
and see if the volume control is affected when COS is asserted?

On my PC, if I press volume down, either on the keyboard or on an unmodified 
USB sound fob then a volume bar pops up in the centre of the screen.  It's 
very visible.

Naturally, there may be a 'correct' way to do this with some sort of built-in 



More information about the App_rpt-users mailing list