evertz hd9084, Instruction Manual, Page: 117 / 126

HD9084 HDTV Caption Encoder Manual
TROUBLESHOOTING Page 6-9
6.3.15. My Modem Connection Hangs-Up Unexpectedly
The following can cause unexplained hang-ups on a modem connection:
RAIN: If there has been any significant rainfall during this time, moisture can get into the lines
and cause power hums and other sorts of phenomenon. This can cause the DC level of
the phone line to vary, which modems can interpret as loss of carrier.
DISTANCE: If the captioner is a long distance from the CO (Central Office) where they are near the
limit of transmission, dropouts can occur if there is not a line booster in place. If there is
a line booster, this can also be a problem if there are grounding issues, etc.
CAPTIONERS MODEM: If the initialization string is setup incorrectly, this can cause the modem to
not function correctly. The user may want to check the modem manufacturer for the
recommended set-up for their particular modem so it is capable of operating in the 1200
to 2400 baud range. Some people that use US Robotics 57.6k modems have reported
difficulties connecting at lower baud rates due to these setup strings.
OTHER SOFTWARE: If there is any other software on the system that uses the modem, it may
have changed the initialization string or be interfering with the modem. On computers
that use a COM-port mouse, the mouse may also interfere with the modem operation if it
is configured incorrectly.
READ THE MANUAL: Be sure the captioners know their system inside and out. They should, at
minimum, be able to supply what their system configuration is.
CALL WAITING: If this service is installed on the captioner’s phone line, it MUST be disabled
before using the modem. If an outside caller tries to call the phone line that the modem
is connected to, the tone that is generated will disrupt modem communications, resulting
in loss of carrier.
ONLY CONNECT TO POTS: (Plain Old Telephone System) For a reliable telephone connection
to the caption encoder a direct telephone line must be used. This line must not
pass through a PBX or similar key device.
Today, many telephone companies digitize the signal within their networks,
unbeknownst to the customer. You may be able to establish a reliable
connection to the caption encoder at 1200 or 2400 baud, but no higher. (This
speed is acceptable for most captioning applications.) In other cases, you may
need to ask the telco for a phone line with higher bandwidth, possibly at extra
charge.
ENSURE THE LATEST FIRMWARE IS INSTALLED: From time-to-time, Evertz may release updated
firmware for the HD9084 to add new features or improve performance. It is
recommended to always check for firmware updates when you encounter a
problem. The firmware release notes will provide some guidance as to whether a
firmware upgrade will address your specific problem.
6.4. BEFORE YOU CALL EVERTZ TECHNICAL SUPPORT
Check for any product upgrades that may address your problem at the Evertz web site
(
www.evertz.com ) and consult your software vendor.
USO
RESTRITO