HP 54645A, User'S And Service Manual

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Sharing of Sources
The source definitions for the simple pattern trigger are shared with the
Pattern 1 and Edge 1 sources of the advanced pattern trigger specification.
Thus, changes to the simple pattern trigger will affect that specification, and
changes to Pattern 1 and Edge 1 in the advanced pattern trigger specification
will affect the simple pattern trigger.
Logical Combinations
In advanced trigger, settings within pattern terms are logically ANDed. Settings
within the second edge term are logically ORed with the first edge term. Thus,
only one of those edge specifications must be satisfied to satisfy the edge term.
TV Trigger
The TV trigger only operates on the analog channels. The TV trigger can be
set to trigger on the vertical interval, Field 1, Field 2, or Line. In Line mode,
the oscilloscope will trigger on the start of the first line that occurs after the
scope starts.
The advanced TV trigger requires two vertical divisions of display amplitude.
On HP 54645D, you must specify either analog channel (A1 or A2) as the
trigger source. You specify the polarity—either positive or negative sync
pulses—and the TV mode. The Field 1 TV mode triggers on the field 1
portion of the video signal, Field 2 triggers on the field 2 portion of the video
signal, and Line triggers on all the TV line sync pulses.
On HP 54645D, pressing Field 1 and Field 2 simultaneously gives vertical
triggering.
You can select the high-frequency reject in the Mode/Coupling menu to
control a 500-kHz, low-pass filter in the trigger path.
Triggering HP 54645A/D Oscilloscopes
Trigger types
3-15