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).