Comtech EF Data SDM-2020 - Manual (Page 151)

SDM-2020 Satellite Modulator Revision 7
Data Interfaces MN/SDM2020M.IOM
12-4
Table 12-2. Specification Summary (Continued)
Video Interface (Terrestrial)
Clock
Accuracy Programmed data rate ± 100 ppm.
Clock Jitter,
Drift And
Wander The interface clock frequency error (drift limit) shall not exceed ± 2.8 ppm.
The rate of frequency change (drift rate) shall not exceed 0.028 ppm/s.
The jitter in the timing of the interface signal transitions shall not exceed 2 ns p-p, measured over a
bandwidth of 1 Hz to 1/100 of the interface clock frequency.
Cable Length,
Typical RG59 180 meters (591 feet)
Belden 8281 250 meters (820 feet)
Auxiliary Function Port
Signals DF (Demodulator Fault, open-collector output).
CD (Demodulator Carrier Detect, TTL output).
Connector 9 Pin D, female.
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.