Comtech EF Data CDM-710G, Installation And Operation Manual

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CDM-710G High-Speed Satellite Modem Revision 1
Clock Modes MN-CDM710G
10–2
Rx Loop-
Timed In Rx Loop-Timed applications, ST is derived from the Rx-Sat clock. Depending
upon the interface, the Tx clock and Rx clock may be the same or different rates.
Buffer Enabled
When the Rx Buffer is enabled, one of several clocks is available to clock receive
data out of the modem and send the received data to the DTE, depending upon the
data interface. The Rx Buffer Clocks include
Tx-Terr (TT or SD), Int Clk (derived
from Int Ref or Ext Ref ) or Ext Clk . Some interfaces require the Tx = Rx data rate
and other allow Tx
≠
Rx.
Figure 10-1. Typical Data Interface (Features Vary By Interface)
Rx Synth
Rx Synth
Tx PLL
Tx PLL
Tx PLL
Tx PLL
Int Ref
Int Ref
ST Synth
ST Synth
Rx Buffer
Rx Buffer
Ext Clk PLL
Ext Clk PLL
Data Interface Card
Ext Clk
ST
TT
(or G.703 SD)
RT
(or G.703 RD)
Ext Ref
Tx-Sat
Rx-Sat
Int Clock
Rest Of Modem