Loopback Features (Terrestrial & IF)

The modem provides for a number of different loopbacks. The Loopback supported are:

IF Loopback – Tx IF port is looped back to the Rx IF port

TX Terrestrial Loopback - Tx Data port is looped back to the Rx Data port after the interface driver/receiver. (prior to the framing unit)

TX Baseband Loopback - Tx Data port is looped back to the Rx Data port after the interface driver/receiver. (after the fraiming unit)

RX Terrestrial Loopback - Receive Data from the satellite is looped back for retransmission to the satellite, providing a far end loopback. (prior to the framing unit)

RX Baseband Loopback - Receive Data from the satellite is looped back for retransmission to the satellite, providing a far end loopback. (after to framing unit)

TX/RX Terrestrial Loopback - provides both Terrestrial loopbacks simultaneously

TX/RX Baseband Loopback - provides both Baseband loopbacks simultaneously

Usage of the modems loopback capabilities in conjunction with the Ethernet data interface can produce undersirable network loops. In order to run any type of data test with an Ethernet interface you must utilize two modems connected back to back. Simply using one modem and a loopback will not produce the desired results.

Loopback Functional Block Diagram

Tx/Rx Loopback Functional Block Diagram