TANDBERG SM6610, Справочное руководство

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Introduction
Page 1-6 Reference Guide: SM6610, SM6615, SM6620 and SM6625 Satellite Modulators
ST.RE.E10152.2
1.3 Summary of Features
1.3.1 MPEG-2 and DVB Compliance
The Modulator normally accepts an MPEG-2 transport stream in either
188-byte or 204-byte packet format. 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.
1.3.2 Data Inputs
The Modulator base unit has two DVB ASI electrical inputs. When fitted
with the SM66XX/HWO/ASI-SPI option, the Modulator has two additional
DVB ASI electrical inputs (making four in total) and one DVB SPI input.
The incoming data may be in any of the following three 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)
1.3.3 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. Rate adaptation may
be switched on or off under user control. See Section 7.3.2, Transport
Stream Rate Adaptation for further details of the rate adaptation function.
1.3.4 IF Output Models
Modulator models SM6610 and SM6620 have a tuneable 50-180 MHz IF
output. Both main and monitor outputs are provided on these models.
1.3.5 L-Band Output Models
Modulator models SM6615 and SM6625 have a tuneable 950-1750 MHz
L-band output. Both main and monitor outputs, and an L-band carrier
combining input are provided on these models. 24 V dc 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.
1.3.6 PREKOR™ Models
Modulator models SM6620 and SM6625 incorporate Tandberg Television’s
proprietary PREKOR™ Dynamic Pre-correction system. This system
corrects non-linear magnitude and phase distortions, and group delay
distortion introduced by the uplink HPA and satellite transponder. It is of
particular benefit when using higher order modulations such as 16QAM.
NOTE…
The SM66XX/SWO/PREKOR software option must be installed to enable the PREKOR™ system.