Product specifications

CDM-Qx/QxL Multi-Channel Satellite Modem with DoubleTalk™ Carrier-in-Carrier® Revision 7
Rear Panel Connectors MN/CDMQX.IOM
3–7
3.3.2 Balanced G.703 Connector Tx/Rx Connector
The Balanced G.703 connection is a 15-pin ‘D’ type female (DB-15F)
connector located on the rear mounting plate of the modulator or
demodulator. If a Modulator and Demodulator are vertically grouped together
as a modem, the data interface connector on the Demodulator switches to
duplex. This feature allows a single data interface connection to be used for a modem instead of
needing a “Y” cable. Otherwise, each module is a simplex data interface.
Table 3-4. Balanced G.703 Interface Connector Pin Assignments
Pin # Signal Function Name Direction
1 Drop Data Input ( - ) DDI– In
9 Drop Data Input (+) DDI+ In
2 Ground GND
10 Not Used
3 Insert Data Output ( - ) IDO– Out
11 Insert Data Output (+) IDO+ Out
4 Ground GND
12 Drop Data Output ( - ) DDO– Out (D&I Only)
5 Drop Data Output (+) DDO+ Out (D&I Only)
13 Insert Data Input ( - ) IDI– In (D&I Only)
6 Insert Data Input (+) IDI+ In (D&I Only)
14 Not Used
7 Not Used
15 Not Used
8 Not Used
3.3.3 Unbalanced G.703 Tx/Rx Connectors
Two female BNC 75Ω connectors are available for unbalanced operation at the
G.703 data rates of T1 (1.544 Mbps), E1 (2.048 Mbps), and E2 (8.448 Mbps).
If a Modulator and Demodulator are vertically grouped together as a modem,
the Tx data input interface connector on the Demodulator becomes active,
allowing duplex operation. Otherwise, the Tx data input connector is used on the modulator and
the Rx data output connector is used on the demodulator.