To fully understand level measurement results, you should be familiar
with the shading of the bar graph, the indications of Pass/Fail status
when limit checking, and the viewing options available in Level mode.
Bar Graph Shading
The bar graph is comprised of up to four contrasting shades:
White
The background color of the graph when limit checking is turned off. Also
the background area within limit boundaries when limit checking is enabled.
Gray
The color of the measurement bar when limit checking is turned off. Also
the color of the measurement bar when limit checking is enabled and the
signal level is within the configured boundaries.
Black/White Diagonal Hash Lines
The area above and below the configured limit boundaries (also described
as the area "out of range").
Black
The color of the measurement bar when the signal level is not within
the limit-set range. This occurs when the top of the measurement bar overlaps
the area of black/white diagonal hash lines, indicating measurement failure
in relation to the selected limit set.
Interleaver Depth (Annex B only)
When viewing a locked digital signal the interleaver depth is displayed
in the BER area. The DSAM supports the following interleaver depth values:
- 1,128
- 2,64
- 4,32
- 8,16
- 16,8
- 32,4
- 64,2
- 128,1
- 128,4 (Optional Purchase Required)
NOTE: If the displayed interleaver depth is greater than the interleaver
depth supported, the BER values are displayed as dashes (-----).
Limit Checking Results
When limit checking is enabled, an overall Pass or Fail symbol and the
name of the selected limit set are displayed directly above the bar graph.
When a level measurement fails to fall within the selected limit-set range,
an up or down arrow appears to the right of the measurement indicating
that the value is too high or too low.
A Pass or Fail symbol also appears next to each level measurement within
the channel.
NOTE: No Pass/Fail information is available when limit checking is
turned off.
Viewing Options
The following viewing options are available to assist you with data assessment.
Press the VIEW softkey. Use the arrow keys to choose the menu item
you prefer and press ENTER to make your selection.
Select Auto Reference to automatically view measurement results
in the best reference setting on the bar graph (Keystroke shortcut: SHIFT
9). NOTE: For best reference setting results you may have to select
the Auto Reference button more than once (up to three times).
Select 5 dB/div or 10 dB/div to adjust the vertical resolution
of the graph for the best viewing.
Select DQI to view a time elapsed
view of level measurements.
Select MiniScan to view the MiniScan measurement screen.
Select Tilt to view the Tilt measurement screen.
Select Pause to suspend measurement updates (Keystroke shortcut:
SHIFT 8).