Figure 10-1. Typical Data Interface (Features Vary By Interface) - Comtech EF Data CDM-710G Installation And Operation Manual

CDM-710G High-Speed Satellite Modem
Clock Modes
Rx Loop-
Timed
Buffer Enabled
Ext Ref
TT
(or G.703 SD)
ST
Ext Clk
RT
(or G.703 RD)

Figure 10-1. Typical Data Interface (Features Vary By Interface)

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.
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.
Tx PLL
Tx PLL
Int Ref
Int Ref
Tx PLL
Tx PLL
ST Synth
ST Synth
Ext Clk PLL
Ext Clk PLL
Rx Synth
Rx Synth
Rx Buffer
Rx Buffer
Int Clock
Data Interface Card
10–2
Revision 1
MN-CDM710G
Tx-Sat
Rest Of Modem
Rx-Sat