Agilent Technologies X Series Manual page 575

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The trigger menus let you select the trigger source and trigger settings for a sweep or measurement. In
triggered operation (basically, any trigger source other than Free Run), the analyzer will begin a sweep or
measurement only with the selected trigger conditions are met, generally when your trigger source signal
meets the specified trigger level and polarity requirements. (In FFT measurements, the trigger controls
when the data acquisition begins for FFT conversion.)
For each of the trigger sources, you may define a set of operational parameters or settings which will be
applied when that source is selected as the current trigger source. Examples of these settings are Trigger
Level, Trigger Delay, and Trigger Slope. You may apply different settings for each source; so, for
example, you could have a Trigger Level of 1v for External 1 trigger and –10 dBm for Video trigger.
Once you have established the settings for a given trigger source, they generally will remain unchanged
for that trigger source as you go from measurement to measurement within a Mode (although the settings
do change as you go from Mode to Mode). Furthermore, the trigger settings within a Mode are the same
for the Trigger menu, the Gate Source menu, and the Sync Source menu that is part of the Periodic
Timer Trigger Setup menu. That is, if Ext1 trigger level is set to 1v in the Trigger menu, it will appear
as 1v in both the Gate Source and the Sync Source menus. For these reasons the trigger settings
commands are not qualified with the measurement name, the way the trigger source commands are.
The settings setup menu can be accessed by pressing the key for the current trigger source a second time.
For example, one press of Video selects the Video trigger as the source. The Video key becomes
highlighted and the hollow arrow on the key turns black. Now a second press of the key takes you into
the Video Trigger Setup menu.
Trigger Setup Parameters:
The following examples show trigger setup parameters using an external trigger source.
Example 1 illustrates the trigger conditions with negative slope and no trigger occurs during trigger
Holdoff time.
Example 2 illustrates the trigger conditions with positive slope, trigger delay, and auto trigger time.
1.5 V
Example 1:
Positive Slope
(no level selected)
Trigger Delay
Example 2:
Negative Slope
0.75 V Trigger Level
Trigger Occurs
Trigger Holdoff Time
Sweep occurs
Auto Trigger Time
and data
processing
completes.
Trigger Occurs
Trigger Delay
vsd44
Trigger
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