Cortelco network adaptor - Manual (Page 19)

Operating Tips and Troubleshooting
A. USB Drivers - The DPA uses standard Microsoft drivers. When
installing the DPA for the first time, you will be prompted by the
computer to install/load drivers. Follow the prompts to identify the DPA
to your operating system.
B. Telephone Handset - The handset must be out of its cradle when
the modem is in use. When the modem is in use, the handset will be
electronically disconnected and you will not be able to talk on or hear
from the telephone handset. This is the primary indication that the
DPA is turned on. Make sure the telephone handset is out of the
cradle until you finish your modem session. Hang up your modem to
reactivate the handset.
C. “Hum” Switch - When using the DPA with a laptop computer, you
may notice a “buzz” or “humming” noise on the handset when the
laptop computer is being powered by its’ external power supply. The
noise is being generated by the computers’ external power supply and
is being picked up by the telephone set due to a ground incompatibility.
On the side of the DPA farthest from the USB I/O cable is a two-
position slide switch. Changing the switch position changes the
ground and should eliminate the “buzz” or “hum”.
This “buzz” or “hum” may not be noticeable on the telephone handset,
however you may hear it on the computer speaker when the modem is
in use. Buzzing or Hum may affect connection rate.
D. Telephone Set Volume Control - The Telephone Set
Volume Control (handset and or speakerphone volume) may impact
your connection speed. KONEXX recommends that the volume
control be set in the mid-range for most telephone sets. Some
AT&T/Lucent / Avaya sets may require the volume set at a lower level.
E. Level Switch on the DPA - The setting you use depends on the
signal level used by the telephone to which the DPA is connected. The
switch setting sequence from high to low is 2-3-1-4. If the phone
system is not listed on the table try switch setting 3 which is the most
common. If you set the Level switch too high, you will hear feedback
through the modem speaker when the modem is in use. If you hear
feedback, set the Level switch to the next lower setting using the
sequence 2-3-1-4 until the feedback disappears.
F. Speakerphones - If your telephone has a speakerphone mode, do
not activate the speakerphone. Speakerphone operation disables the
telephone handset jack that the DPA uses to transmit and receive
data.