| Unity 552 User’s Manual |
| Table 4.3: Signal Quality Information |
|
|
Parameter | Description |
|
|
Modulation | 8PSK/QPSK/S1 |
|
|
RF Switch/Pol | If IRD is configured for Universal LNB, H or V are valid. Specify RF port |
| for |
|
|
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 |
| 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. |
|
|
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.
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