JDS Uniphase DSAM-1500, User Manual

Page: 234 / 362

Chapter 8 Measure Mode – Basic Tab
Return Loopback
194 DSAM Help User Guide Rev. 001
DQI Digital Quality Index where 0 = worst and 10 = best.
Min The lowest DQI value generated since starting the node.
Graph Changes only if the levels are different from the levels of the previous
trace.
Graph Information
Bar
This area consists of the total time in seconds it takes to display a
complete trace and the number of seconds per division.
Changing/Editing
the Channel Plan
To change the channel plan
1 Press the Settings softkey.
2 Refer to “Downstream Plans” on page 78 .
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 arrow keys to move the marker to the
preferred channel then highlight this option from the
View
menu.
– MiniScan – Displays the MiniScan screen.
– Tilt – Displays the Tilt screen.
– Full Scan – Displays the Full Scan screen.
– Constellation – Displays the Constellation screen.
– QAM Ingress – Displays the QAM Ingress screen.
– Pause (Shift, 8) – Suspends measurement updates.
3 Press ENTER .
Return Loopback
The Return Loopback mode enables you to quickly perform frequency
response measurements of active or passive field devices using a
single meter. A CW signal may be generated from the DSAM unit and
21128026 R001 DSAM Help User Guide.book Page 194 Thursday, February 5, 2009 2:02 PM