Musicam FieldFone II, Руководство пользователя

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F I E L D F O N E I I U S E R S G U I D E
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high bit rates. In areas where high bit rate connections can be
established but cannot be supported over long periods of time, select a
lower bit rate before re-dialing.
The threshold at which the modem will automatically consider a
connection acceptable is user definable. If a small amount of line errors
can be tolerated, you can have the FieldFone II accept this noisier line.
This can yield wider bandwidths at the expense of possible line errors
(audio drop-outs). The rate threshold setting uses the command
sequence:
<Operation><Modem Control><Rate Thrshld>
where the choices are HIGH or LOW
Setting the rate threshold to HIGH will allow less errors in the
connection, resulting in a lower bit rate connection. The factory default
setting is ‘LOW’, but should be changed when an occasional repeated
frame cannot be tolerated.
In some cases, the line condition may deteriorate after an acceptable
connection is established, or there may be random error bursts that may
affect audio quality.
FieldFone II
provides
a real time line condition monitor (shown
here) to display the current condition of the
line in use.
The line condition is continually displayed as a horizontal bar, where
the length of the bar indicates the line condition. The longer the bar,
the better the line. The number to the right of the bar indicates the
number of frames with CRC errors per second. The top line of the
display shows the connect bit rate and the connection time. This
display appears as a default display after any connection is established.
Pressing the up arrow cancels the line condition display and returns
you to the menu display. To return to this display at any time, use the
keypad sequence:
<Status>
If the line condition deteriorates to the point where an acceptable
connection cannot be maintained, the next layer of protection will be
enabled, and the connection will
automatically be terminated. The LCD
display of the FieldFone II will show: