SM6630 and SM6635 Satellite Modulators
6
1.4 Summary
of
Features
1.4.1
MPEG-2 and DVB Compliance
The Modulator normally accepts an MPEG-2 transport stream in either 188-byte or
204-byte packet format when operating in DVB-S/DSNG or DVB-S2 CCM modes.
Alternatively, an internally generated Pseudo Random Binary Sequence (PRBS) or
Null Packets source may be selected for test purposes. This does not require the
presence of a transport stream input.
1.4.2 Data
Inputs
The Modulator base unit has two DVB ASI electrical inputs. When operating in
DVB-S/DSNG or DVB-S2 CCM modes, the incoming data may be in any of the
following four formats:
!"
188-byte packets (188 data bytes, contiguous packets)
!"
204-byte packets (188 data bytes and 16 RS coding bytes; the coding bytes
are ignored)
!"
204-byte packets (188 data bytes and 16 dummy bytes)
!"
Unframed data, i.e. without MPEG-2 sync bytes
When operating in DVB-S2 ACM mode, the incoming data may only be in
BBFRAME format.
1.4.3
Transport Stream Rate Adaptation
The modulator is capable of performing transport stream rate adaptation with PCR
correction, allowing it to be used at a fixed symbol rate irrespective of the transport
stream input data rate.
1.4.4 IF
Output
Model
Modulator model SM6630 has a tuneable 50-180 MHz IF output. Both main and
monitor outputs are provided on this model.
1.4.5
L-Band Output Model
Modulator model SM6635 has a tuneable 950-1750 MHz L-band output. Both main
and monitor outputs, and an L-band carrier combining input are provided on this
model. 24 Vdc power and a 10 MHz reference frequency output, both switchable,
are provided via the main L-band output connector for use by an external
frequency up-converter.
