Tahoe 671, User Manual

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2
2. Interfaces
Following connectors are found on the rear panel of the modem:
2.1. G.shdsl
It is a 6-pin RJ-11 connector used to connect the leased line. The
line should be connected to the two central pins (3 and 4). The
polarization of a line is not important.
2.2. Serial console
The RS-232 serial console is used for modem management. It has
a DB9/M connector and works as a DTE, i.e. a null-modem cable should
be used to connect it to a PC. Only three lines (written in bold) are
necessary for transmission. Terminal settings are 9600 bps, 8 data bits, 1
stop bit, no parity, no handshaking.
3
2.3. G.703
The G.703 port has a RJ-45 connector. The G.703 standard
doesn’t specify the connector pinout, but the pinout used in Tahoe
devices is the most common in the industry, thus in most cases a regular
straight patch-cord may be used to connect the card to the external
device.
Anyway the pinout should be carefully checked before connecting
the DCE device. The RX+ pin of the card should be connected to the TX+
pin of the other device, the RX- pin to the TX- pin, TX+ to RX+ and TX- to
RX-.
Pin Name
1 DCD
2
3
4
5
6
RXD
TXD
DTR
GND
DSR
Description
carrier detect, transmission readiness signaling
data received from the PC
data sent by the modem to the PC
active, when the PC is switched on
signal ground
active, when the modem is switched on
7 RTS
used by the PC to inform that is has data to send
8 CTS
used by the modem to permit data transmission
9 RI
ring indicator (signal used in telephone modems)
G.shdsl
serial
console
G.703
power
switch power
connector
O
I
2.3
Pin Function
1 -
2
3
4
5
6
line
line
-
-
-
Pin Signal
1 Tx+
2
3
4
5
6 Tx-
-
Rx+
Rx-
-
7
8
-
-
2
2.1
2.2