The QAM Power Level and Max Adjacent Channel Delta are updated in real-time. The MER, Pre BER, Pre ES, Post BER, Post
ES and SVES measurements are snapshots upon entering this screen.
Constellation
Tab: Constellation is an ideal tool to identify QAM modulator problems. The following measurements are reported:
QAM Power Level (numeric in dBmV)
MER (numeric in dB) is an indication of the operating margin of the system
Pre BER & Pre Error Seconds (numeric) is the error rate of the incoming signal prior to being corrected FEC circuitry
Post BER & Post Error Seconds (numeric) is the error rate of the signal after the FEC has corrected all the possible errors
Severely Error Seconds (numeric)
Constellation (graphic)
Max Adjacent Channel Delta (numeric in dB)
The MER, Pre FEC, Post FEC, and Constellation diagram are updated in real-time. The QAM Power Level and Max Adjacent
Channel Delta are snapshots upon entering this screen.
The following information is displayed for both analog and digital signals:
Channel
Frequency
Limits Location (Tap, Ground Block, or Set-Top)
Graphic limit indicators are provided for all graphically displayed signal levels. Numeric data that is outside of limits are displayed in
red.
CX100/110/120/150/180 series e-Manual D07-00-002 Rev B01
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