Wegener Communications UNITY 4600 - Manual (Page 20)

U NITY 4600 U SER ’ S M ANUAL
800032-01 Rev. F 12 www.wegener.com
Service Descriptor Service Descriptors are text entries in the Service Descriptor table (SDT, defined per a DVB
standard). Service Descriptors are used to give text names to the Programs within transport
streams.
Service Settings That part of the Unit Settings which allow for the local detection, decompression, and output (or
"display") of a program's services.
Setting, Last
Commanded The most recent Unit Setting requested by a user (local or network) command. This value is non-
volatile.
Setting, Last
Successful The most recent Unit Setting, which is NOT a Temporary Setting, at which the IRD was able to
deliver services while free of alarms. This may also be the Last Commanded setting or it may be the
attempted (Transient) setting at which auto-recovery was successful. This value is non-volatile.
Setting, Permanent That non-volatile Unit Setting which the IRD will attempt, if in Normal Operation, after a unit reset.
This will be the Last Commanded setting unless, since that command was issued, the IRD had
executed an Auto-Recovery and successfully acquired at one of the Preset settings. In other words,
the Permanent Setting is the most recent of the Last Commanded and Last Successful Settings.
Setting, Temporary A special volatile unit setting with a timed expiration period. The command to invoke this special
setting and the subsequent success of the IRD to find services at this setting does not affect the non-
volatile value of the Last Commanded or Last Successful Settings. Also, if the compliant IRD
receives a command to change its Permanent Setting while in a Temporary Setting, the Temporary
Setting will
not be aborted, but the new Permanent Setting will be recorded in NVRAM as the Last
Commanded setting and the Permanent Setting pointer will refer to that.
Setting, Transient A volatile Unit Setting used for immediate acquisition of services. Transient settings are either
Temporary settings (see above) or Presets used for attempted acquisition during Auto-Recovery. If,
in the case of Presets, the attempt is successful, those settings become Permanent Settings.
T
MRA
Maximum Recommended Ambient Temperature, the highest operating temperature for which the
unit is rated
Transport Stream
(or MPEG Transport
Stream) A multiplex of several data streams, each of which is borne in transport packets, 188-byte blocks
containing a sync word, header information (including a PID), and payload data. This multiplex
includes PSI data tables, programs, padding, and floating PIDs such as those used by COMPEL

network control.
Warning A condition or notification of (1) a condition that may compromise the proper performance of your
U4600; or (2) any non-alarm condition that should be brought to local user’s attention.
Table 1.3: Glossary of Terms
Term Definition