Comtech EF Data CDD-880, Installation And Operation Manual

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CDD-880 Multi Receiver Router MN-CDD880
Ethernet-based Remote Product Management Revision 2
6–23
Column Description
Rx MODCOD
Use the drop-down list to select the demodulation type and VersaFEC rate (MODCOD):
•
QPSK 0.488
•
8-QAM 0.642
•
16-QAM 0.829
• QPSK 0.533 • 8-QAM 0.711 • 16-QAM 0.853
•
QPSK 0.631
•
8-QAM 0.780
• QPSK 0.706 • 16-QAM 0.731
•
QPSK 0.803
•
16-QAM 0.780
Rx Spectrum Invert Use the drop-down list to select Spectrum Inversion operation as either Normal or Inverted .
Rx Descram Use the drop-down list to select Rx Descrambling as either Off or Normal .
Eb/No Alarm Pt
(0.1 to 16.0 dB) – Enter the Eb/No Alarm Point value, in dB. This value, as calculated by the
demodulator, is the energy per bit (Eb) divided by the noise spectral density (No).
When ACM is enabled, the CDD-880 will issue an alarm only if the
demodulator is at the lowest available MODCOD (BPSK).
Circuit ID (4 to 24 characters) – Enter an identification label for the demod. Click [Submit] to save.
Acquisition Range
The Acquisition Range is programmable in 1kHz increments, subject to the following:
•
Below 64 ksymbols/sec: ±1 to ±(Rs/2) kHz, where Rs = symbol rate in
ksymbols/sec.
• Between 64 and 389 ksymbols/sec: ±1 up to a maximum of ±32kHz.
• Above 389 ksymbols/sec: ±1 to ±(0.1Rs) kHz, up to a maximum of ±200 kHz.
Use these guidelines to enter the Acquisition Range. Click [Submit] to save.
6.3.3.2.2 Configuration | WAN | ACM (Adaptive Coding and Modulation)
Appendix H. V
ERSA
FEC RETURN LINK ACM (ADAPTIVE CODING
AND
MODULATION)
Use this page to inspect CDD-880 ACM operations. Figure 6-13 shows the page as it appears
with the CDD-880 equipped with a single dual demodulator card.
Figure 6-13. Configuration | ACM Page
Return Link (Inbound) ACM allows the CDM-840 Gateway Router to dynamically adjust the
VersaFEC MODCODs that are sent to each CDD-880, based upon the conditions between the
remote and the hub. These conditions include antenna size, look angle, satellite band, and the
current environmental conditions. The CDD-880 automatically and periodically sends its Rx