Tahoe 671, User Manual

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3. Modem configuration using built-in
keyboard and LCD
The easiest way to configure a modem is to use the four-button
keyboard and the LCD. After switching the power on, an information
about the modem type, the line throughput and state will be displayed:
Four-letter code in the bottom right describes the DSL line state:
¡
BOOT - booting of the G.shdsl transceiver
¡
IDLE - transceiver inactive
¡
DOWN - transceiver active, line not synchronized
¡
SYNC - line synchronized, data may be transmitted
The G.703 link status is described using two letters in the upper
right corner of the LCD. In case of unframed mode letters “UC” may
appear. Letter “U” signals the unframed mode and “C” means that the
carrier signal was detected.
In the case of unframed mode letters “SC” may appear there.
Letter “S” means that the modem is synchronized to the E1 stream.
Letter “C” again signals, that the carrier was detected.
If only “C” is
displayed, then the G.703 signal is present, but the converter is unable to
synchronize to it. Perhaps the signal detected is an unframed signal.
On the right of the display there is a keyboard with “up”, “down”,
“Escape” and “Enter” keys. By pressing up/down buttons you may
browse the configuration menu:
¡
speed setting
¡
modem type setting (Master/Slave)
¡
line modulation selection
¡
CRC4 setting
¡
G.703 port line coding, sensitivity and range
¡
test loopbacks
¡
console throughput
¡
language selection
¡
storing settings in the EEPROM memory
¡
connection reset
¡
modem reset
Each pressing of the “Escape” button causes the return to the
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primary display with modem type and state. Pressing of the “Enter”
button selects given menu option.
3.1. Throughput setting
After pressing Enter the throughput may be set using up/down
buttons. It may be chosen from 128-2048 kbps range. In the framed
mode the first number depicts the DSL line speed, while the second one
- a sum of G.703 timeslots used for transmission. It is 64 kbps lower
than the first one, because the DS0 synchoronization timeslot is also
being transmitted over the DSL line, while it is not used for the data
transmission over the G.703 link.
When the throughput is set to 2048 kbps (1984) and “up” button
is pressed the letters “unfr” will appear in the brackets. It means that
the unframed mode is enabled and whole 2048 kbps are used for data
transmission.
In the framed mode the selection of G.703 timeslots used for
data transmission is done automatically depending on the throughput
set. Timeslots 0 (synchronization) and 16 (signaling) are selected first,
then the subsequent timeslots from 1 to 15 and from 17 to 31:
NOTE: The same throughput must be set on both modems.
Tahoe 671 UC
2048 kb/s
BOOT
Line rate:
2048 kb/s (1984)
Throughput Timeslots used
128 kbps 0, 16
192 kbps
256 kbps
...
1024 kbps
0, 1, 16
0, 1, 2, 16
...
0, 1, 2, 3,..., 13, 14, 16
1152 kbps
0, 1, 2, 3,..., 13, 14, 15, 16
0, 1, 2, 3,..., 13, 14, 15, 16, 17
... ...
1984 kbps 0, 1, 2, 3,..., 28, 29, 30
2048 kbps 0, 1, 2, 3,..., 28, 29, 30, 31
1088 kbps
Line rate:
2048 kb/s (unfr)
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3.1