s100u notes [was Re: [Asterisk-Users] S100U hissing noise..]

[Michael]

>>> steve at szmidt.org wrote a 1.2KB message. i replied .....................................
> >
> > I have got a hissing/humming noise on my handset that is
> > connected to the S100U USB device..
> >
> The USB port is VERY sensitive to static electricity. It's not rated 
> production quality, only proof of concept. You should really use 
> the new TDM400P which supports one to four lines.

Some notes about the s100u (which i've finally managed to somewhat
stabilize and cooperate with an x100p in the same box).

-- Static .  People have reported static sensitivity problems with the device.
   I found it to be very unstable until i noticed that both the usb and
   pstn connections are very sensitive to motion.  I wrapped a single strand of
   insulated wire a few times around the device, including both the usb and phone 
   wires in the binding.  I also mounted it on a water pipe in our basement 
   (where the system is).  This seems to prevent the connections from breaking 
   and it also keeps the device out of the way.

-- Integration.  The entire process of loading the modules is highly dependent
   upon order of hardware detection and configuration.  When attempting to reload
   the wcusb module make certain to unload your usb controller driver (usb-uhci,etc).
   before reloading ..  Make sure you run ztcfg after reloading zaptel modules.
   This may be done automatically in some cases.  Also, zttool is your friend.
   If you dont have it on your system you probably need to install newt.

-- IRQs.  Configure your system such that your ethernet/sound/zaptel/usb
   devices are not sharing interrupts.  This is very important, these
   things generate loads of interrupts.

$0.02,


--Michael.


--
 Michael Jastremski  | Network Engineer
 Megaglobal Networks | Megaglobal.net
 Open Photo Project  | Openphoto.net
 West Philadelphia   | Westphila.net