Q-Flex Satellite Modem Installation and Operating Handbook
9-1
Chapter 9
Data Interfaces
The modem provides Ethernet IP interfaces as standard plus options for LVDS, EIA530
(RS422, V.35, and RS232), IDR, HSSI, G.703 (balanced and unbalanced), Quad E1, IP
traffic and Eurocom D1 interfaces. There are four data interface positions on the modem.
The P3722 G.703 option card supports E1/T1/E2/T2/E3/T3 data rates. Both balanced RJ45
and and unbalanced BNC connectors are available.
The P3721 IDR option must be fitted in an upper interface position.
1:1 Redundancy Operation
The G.703 interface needs to be specifically configured for 1:1 operation. The 1:1 G.703
mode controls what happens when power is removed. If the power is lost in
Normal
mode
then the G.703 input and output are joined in order to ensure that if the G.703 signal is
looped through multiple equipment then the other traffic is not affected by a break in the
G.703 line. If the power is lost in
1:1
mode then the G.703 output goes high impedance,
allowing the online modem in the 1:1 pair to carry the traffic.
‘Y’ cables are normally used with the terrestrial interfaces. The IP interface requires
separate but parallel connections to the network.
Handshake Lines
Many interfaces provide optional control lines (such as RTS/CTS etc). It is generally better
to use these if they are available.