Tainet T-288C, Руководство пользователя

Страница: 40 / 131

FRONT PANEL LCD AND MENU-DRIVEN 3-15
3.5 Detailed Description of the menu tree
3.5.1 STATUS MENU
ITEM NAME COMMAND DESCRIPTION
TX LEVEL= -XX dBm AT%S Transmitted signal level. This value is equal to the
" TX level" of config modem. Normally, for the
2w leased line and the dial line, the recommended
value is between -7 and -10dBm. A higher level
may create an interference. 4w leased line should
be between 0 and -31dBm. It can be increased of
in order to obtain a more satisfactory S/N ratio
(siganl to noise ratio) by setting a higher level as
possible, but a saturation of the active
transmission equipment should be avoided. The
Tx level level should be setting under -8dBm
while to operating V.34 mode.
RX LEVEL= -XX dBm AT%S Received signal level. This value is the result of
the line attenuation from the transmitted signal.
Normally, the RX level of 2w leased line and the
dial line is between -15 and -33dBm while the
level of 4w leased line is between -10 and -
26dBm.
S/N. RATIO=XX dB AT%S Signal to noise ratio. The bigger the S/N ratio, the
better quality of a line is. A higher operating
speed needs a higher S/N ratio. Normally, the
S/N requirement of running 14400 bps should be
more than 24 dB while to operate at 9600 bps, a
S/N better than 20 dB is required.
F-SHIFT=X.X Hz AT%S Frequency-shift (offset). It is the shift of the
carrier central frequency caused by the
transmission link. This shift normally should be
less than + / - 7 Hz. The smaller is better.
F F-SHIFT=X.X Hz AT%S Far end frequency-shift (offset). The frequency
shift of the far end received carrier signal.It
normally should be less than +/- 7 Hz. The smaller
is better. The value will not accurate once level is
too small from the remote site.
DELAY=XXXX ms AT%S Round trip delay time. This delay is caused by a
round trip of a long distance line , especially in a
satellite circuit. Usually, round trip of a satellite
link shall create a time delay of 0.5 second
(500ms). The modem will accept a maximum time
delay of 1.5 seconds for V.34 mode, 2.1 sec for
V.32/V.32bis (This value is provided only when
operating on 2-wire of V.32 /V.32bis / V.34).