Comtech EF Data SDM-2020, Installation And Operation Manual

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Data Interfaces SDM-2020 Satellite Demodulator
A–60 Rev.3
Table A-34. SMPTE-310M Specification Summary (Continued)
Monitor and Control
Monitored Functions TX – PLL Lock (monitors presence of input data)
TX – State of RTS input on auxiliary function port
TX - FPGA load failure.
RX - FIFO Underflow/overflow.
RX - PLL lock.
RX - FPGA load failure.
Controlled Functions Interface Loopback.
Interface Loop-through
General
Framing Formats
(to be provided by the
demodulator, not this
interface) 187 (no framing, pass-through mode).
188 (DVB/MPEG2 frame consisting of a sync. byte and 187 data bytes).
204 (frame consisting of sync. byte , 187 data bytes and 16 Reed-Solomon
check bytes).
Environmental
Operating Temperature
Storage Temperature
Humidity
0 to + 50
°
C (32 to + 122
°
F)
-40 to + 70
°
C (-40 to +158
°
F)
Up to 95% non-condensing.
Physical
Size SDM-2020 plug-in module compatible.
Hot Pluggable Not required. Unit power is turned off prior to removal or insertion of the data
interface.
A.7.3.2 Interface Loopback Mode
Refer to Figure A-18.
In loopback mode, data entering the TX connector is returned to the RX output connector
after passing through the interface. The data entering the interface at the TX input is
routed all the way through the TX path and out to the modulator at J1. All TX signals
going to the modulator are routed back to the RX path in place of the normal signals,
which would be coming from the demodulator.
•
In a Modulator, TX data continues to enter the modulator and is TX during loopback.
•
In a Demodulator, satellite data is not routed through the SMPTE-310M Data Interface.
A.7.3.3 Interface Loop-Through Mode
In loop-through mode (Modulator Only), operation is the same as in loopback mode,
however, the test mode LED indications are not activated.