Wegener Communications IPUMP 562 用户手册

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800092-01 Rev. A
 43
Unity 552 User’s Manual 
Table 4.3: Signal Quality Information
4.4  Frequency Tagging
General 
Rules
Frequency Tagging is a mechanism that is used to ensure that an IRD is locked to desired 
carrier settings. Sometimes, due to minor offsets in LNB and frequency errors, tuning may 
be off by a couple of MHz. To prevent locking to some other near by (adjacent) carrier while 
looking for an intended carrier, the acquired carrier contains "frequency tags."   These tags 
are inserted in 
Compel
 control stream at the uplink to identify the intended carrier frequency. 
Traditionally, the tags have been sent at a rate of every 100 or 125 ms. 
The 
iPump 562
 supports both single and multiple tags. A carrier settings with "Tag Site" 
number, specifies which of the possible tags the IRD need to use. The 
iPump 562
 allows for 
Tag Site designations from 0 to 15, inclusive. The tag '15' is reserved for an exception. If the 
Carrier Setting shows Tag Site '15', the Carrier Tags are not required. 
The SCPC Frequency Tag Protocol Functional Specification (WCI #16803) gives more 
details.
Parameter
Description
Modulation
 8PSK/QPSK/S1
RF Switch/Pol
If IRD is configured for Universal LNB, H or V are valid. Specify RF port 1-4 
for four-port RF configuration. 
Carrier
The downlink frequency specified in MHz with up to two decimal places. 
This value’s absolute difference with the LNB LO frequency is used as 
specified in the technical specifications.
Data_rate
Data rate is specified in Mbps with up to three decimal places. See the 
technical specifications for the applicable range.
Fec_rate
The inner FEC code ratio and can have one of the values specified in the 
technical specifications.
Tag_site
Value of 0-14 (15 is a special NO Tag case) specifying the location of this 
carrier’s tag frequency
[program]
The program number from the MPEG Program Association Table. This must 
be number from 1 to 65535. If omitted or an ‘*’ is entered, the unit will select 
the first available program stream. Note that this number points to the PID 
for the Program Map Table for what we might call a “service” (a single video 
channel and associated audio signals).
Label
A string of characters for identification.