Wegener UNITY4000 Instruction Manual page 75

Page 75
FLUTTER Ð An LED that is ON for 50 Ms and OFF for 50 Ms, with the pattern continuing
for some time, is said to ÒFlutter.Ó See Table 13, Page 30. Also, see ÒBlinkÓ and
ÒFlash.Ó
MCPC Ð Multiple-Channel-Per-Carrier. Means that one or more services or programs
are present on a particular radio-frequency carrier.
NTSC Ð National Television Standards Committee. This is a shorthand description
for the standard 525-line, 30-frames-per-second analog baseband television signal
format used in the US
MPEG, MPEG Transport Stream Ð Moving Picture Experts Group. This catchall
abbreviation is used to describe the digital compression (redundancy reduction) of
linearly-digitized audio and video signals as well as the mode of multiplexing and
transporting that compressed data. The Transport stream is a packetized system
consisting of a sequence of 188-byte packets, each with a sync-byte and a specific
payload identified by a payload ID (or PID). The stream contains packets not only for
the compressed audio and video, but also auxiliary data, program information and
allocation data, and conditional access information.
PID Ð Payload Identifier (or ID). See ÒMPEG.Ó
PROGRAM Ð A single video channel and associated audio signals.
QPSK - Quadrature Phase Shift Keying. This is a popular mode of transmitting digital
information by varying the phase of a radio-frequency carrier.
SCPC Ð Single-Channel-Per-Carrier. Only one service or program is present on a
particular radio-frequency carrier.
SETTINGS TABLE Ð An internal table of alternate carrier/program settings stored in the
IRDs non-volatile memory (remembered through power cycles). This table may be
used in the following ways: (1) If an IRD is unable to acquire the commanded carrier,
then it will, after an appropriate time-delay, search for and lock onto any carriers in the
table it may be able to find. (2) If local control is enabled, a user may, through the
front-panel or terminal command, tune the IRD to a new setting found in the table
using the shorthand of the Settings Table entry number.
WARNING Ð A highlighted statement ÒwarningÓ the reader to use care so the
equipment is not damaged, or a person injured. (See ÒCautionÓ)
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