Comtech EF Data SDM-2020 - Manual (Page 143)

SDM-2020 Satellite Modulator Revision 7
Data Interfaces MN/SDM2020M.IOM
11-8
11.1.4 G
ENERAL
T
RANSMIT
S
PECIFICATIONS
11.1.4.1 T
RANSMIT
2047 P
ATTERN
G
ENERATION
The unit supplies a 2047 test pattern substitution into the TX data path when commanded
by the host unit.
11.1.4.2 I
NPUT
P
ORT
R
ETURN
L
OSS
Frequency Range
(kHz)
Return Loss
(dB)
Data Rate/40 to Data Rate/20
Data Rate/20 to Data Rate
Data Rate to 1.5 x Data Rate
12
18
14
11.1.4.3 T
RANSMIT
S
PECIFICATIONS
Parameter Specification
AIS/Data Fault Detection The unit provides AIS/Data fault detection on the incoming TX data stream.
TX AIS Assertion The unit provides AIS substitution into the TX data path when commanded
by the host unit.
RX Output Stable The unit provides data stable into the RX data path when installed in the
modulator. Either RX data stable is removed when interface loop-back or
interface loop through is turned ON.
Clock Activity Detection When installed in a modulator the unit provides activity detection for TX
Terrestrial Clock. TX clock activity faults are communicated to the host unit
and the fallback is SCT.
TX PLL Fault Detection The unit provides TX PLL fault detection. A fault is indicated upon the failure
of either the G.703 clock recovery circuit or the TX clock dejitter circuit.
When fault detection occurs the SCT is selected.
FPGA Program Error
Detection/Reporting The unit detects TX and RX FPGA programming errors and report errors to
the host unit.