Figure 1-3 Clock Source Options - Datum Systems PSM-500 Installation And Operation Manual

PSM-500/500L/500LT SCPC Satellite Modem
Send Data
From
Interface
Send
Timing To
Interface
Terminal
Timing
From
Interface
External Send Timing Input
(Rear Panel)
External External
Reference Input
Reference PLL
(Rear Panel)
Receive
Data To DATA
Interface
Receive
Timing To
Interface
External
FIFO Clock
From
Interface
Bit Rate NCO
These Clock sources may be used in various ways in a system implementation to provide correct
timing at a destination. Each of the clock sources can be set either from the front panel or from an
external monitor and control system.
PSM-500/500L/500LT - Rev. 0.91
DATA
Terminal
Timing
Internal
Reference
Oscillator
Transmit Clock Sources
OUT IN
Receive FIFO
Buffer
OUT IN
From Modulator
bit timing
"Internal"
Receive Clock Sources

Figure 1-3 Clock Source Options

CLOCK
Bit Rate NCO
From
Receive
Clock
Optional Reed-Solomon Decoder
& IBS Multiplexer
Demodulator RCV
CLOCK
FIFO output clock selected from
"RCV Clock", "Internal", "External"
or "Mod Clock". Selection of "RCV
Clock" bypasses the FIFO buffer.
Description
Modulator
Modulator bit clock source is
selected from "Internal", "Terminal
Timing", "External" or "RCV
Clock". The Send Timing is
always an output from the modem.
DATA
Demodulator
CLOCK
Demod output
clock is phase
locked to receive
bit timing
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