Radyne DMD2050, Operation Manual

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Theory of Operation DMD2050 Universal Satellite Modem
3-10 TM110 - Rev. 1.3
3.6 DMD2050 Clocking Options
The following paragraphs define the types of clocking options available to the user at the Front
Panel of the DMD2050. Refer to Figure 3.9 for clocking and polarity.
3.6.1 Clock Selection
As shown in Figure 3-9, both the Tx Clock and the Buffer Clock source may be independently
locked. Clock sources may be:
ƒ
SCT (Internal Oscillator)
ƒ
SCTE (External Tx Terrestrial Clock)
ƒ
EXT BNC (External Clock Source)
ƒ
Rx Satellite Clock (Loop Timing)
ƒ
EXT IDI (Drop and Insert Clock)
For loop timing applications the SCT Clock Source can be selected to be Rx Satellite Clock.
SD
TT
Tx CLK
SRC
High Stability
Oscillator
ST
CLOCK &
DATA
EXT REF
EXTERNAL
INTERNAL
SCT CLK
SRC
REF FREQ
SRC
SCT
SCTE
TRANSMIT
RECEIVE
CLOCK & DATA
RECOVERY
EXT CLK
EXT BNC
SCT
SCTE
RX SAT
RT
RD
SCR
BUFFER CLK
SRC
CLOCK
RECOVERY
EXT IDI
IDI
DMD2050 CLOCKING AND POLARITY
MODULATION
HIGH STABILITY
DEMODULATION
J19
J19
J10
J16
J8
CLK POL
DATA POLARITY
NORMAL
INVERTED
AUTO
INV. TERR&BASE
INVERT NONE
INV. BASEBAND
INV. TERR DATA
DATA POLARITY
BUFFER CLK POL
NORMAL
INVERTED
INV. TERR&BASE
INVERT NONE
INV. BASEBAND
INV. TERR DATA
Figure 3-9. Clocking and Polarity Diagram