2 B L Oopback Features (Terrestrial & If) - Radyne DMD50 Installation And Operation Manual

DMD50 Universal Satellite Modem
3.6 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 Terrestrail Loopback - Receive Data from the satellite is looped back for
to the satellite, providing a far end loopback. (prior to the framing

RX Baseband Loopback - Receive Data from the satellite is looped back for
to the satellite, providing a far end loopback. (after to framing unit)

TX/RX Terrestrial Loopback - provides both Terrestrail 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.
MN-DMD50 Revision 4
Theory of Operation
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