DMD2050E Universal Satellite Modem
3.3
Internal Clock
The time and date is kept in order to 'time-tag' system events. User can change the Internal
Clock via the front panel, Web Browser or Terminal ports.
3.4
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
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
•
IMPORTANT
Using the loopback with the Ethernet data interface causes unwanted network loops.
Before you do any type of data test with an Ethernet data interface, connect two
modems back-to-back. Doing the test with one modem and a loopback does not give
correct results.
MN-DMD2050E Revision 2
Theory of Operation
unit)
3–10