JDS Uniphase DSAM-1500, Руководство пользователя

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Chapter 8 Measure Mode – Basic Tab
QAM Ingress
DSAM Help User Guide Rev. 001 187
Graph Displays signal level on the Y-axis. A vertical bar is displayed and the
height of the bar represents the signal level.
Symbol Rate
Transmit Status Indicates whether Tx is enabled or disabled.
View Menu
To access different functions and shortcuts to other tests
1 Press the View softkey.
2 Using the arrow keys, select one of the following options:
– Single Channel – Displays measurements one channel at a
time. First, use the numeric keypad to enter the channel
number then highlight this option from the
View menu.
– Constellation – Displays the Constellation screen.
– Upstream Spectrum – Displays the Upstream Spectrum
measurement mode.
– Downstream Spectrum – Displays the Downstream Spectrum
measurement mode.
3 Press ENTER .
QAM Ingress
The QAM Ingress mode is a line plot which graphs signal error versus
frequency of QAM signals. This mode supports Ingress Under Carrier
for 64 QAM and 256 QAM signals. (Additional purchase required.)
The QAM Ingress mode enables you to:
– View a graphic depiction of the signal
– View the QAM type (64 or 256)
– View the channel number
NOTE
For information about how to read the graph, see “Reading Mea-
surement Graphs” on page 196 .
The number of symbol changes (signaling events) made to the
transmission medium per second using a digitally modulated signal or a
line code. The Symbol Rate is measured in baud (Bd) or
symbols/second. The default value is 1.28.
21128026 R001 DSAM Help User Guide.book Page 187 Thursday, February 5, 2009 2:02 PM