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Making Measurements
Using Limit Lines to Test a Device
Running a Limit Test 1. To access the limits menu and activate the limit lines, press:
Reviewing the Limit Line Segments
The limit table data that you have previously entered is shown on the analyzer display.
• To verify that each segment in your limits table is correct, review the entries by
pressing:
and
• To modify an incorrect entry, refer to the “Editing Limit Segments” procedure, located
earlier in this section.
Activating the Limit Test
To activate the limit test and the beep fail indicator, press:
NOTE Selecting the beep fail indicator is optional and will add
approximately 50 ms of sweep cycle time. Because the limit test will sti ll work
if the limits lines are off, selecting is also optional.
The limit test results appear on the right side on the analyzer display. The analyzer
indicates whether the filter passes or fails the defined limit test:
• The m essage FAIL will appear on the right side of the display if the limit test fails.
• The analyzer beeps if the limit test fails and if has been selected.
• The analyzer changes the color of the trace to flashing red where the measurement
trace is out of limits.
• A TTL signal on the rear panel BNC connector "LIMIT TEST" provides a pass/fail
(5 V/0 V) indication of the limit test results.
Offsetting Limit Lines The limit offset functions allow you to adjust the limit lines to the frequency and output
level of your device. For example, you could apply the stimulus offset feature for testing
tunable filters. Or, you could apply the amplitude offset feature for testing variable
attenuators, or passband ripple in filters with variable loss.
This example shows you the offset feature and the limit test failure indications that can
appear on the analyzer display.
System
LIMIT MENU
LIMIT LINE
LIMIT LINE ON
EDIT LIMIT LINE
SEGMENT
System
LIMIT MENU
LIMIT LINE
LIMIT TEST ON
BEEP FAIL ON
BEEP FAIL ON
LIMIT LINE ON
BEEP FAIL ON