Technical data

Trigger Commands 33
Agilent Infiniium 9000 Series Oscilloscopes Programmer's Reference 1001
Advanced Pattern Trigger Commands
Logic triggering is similar to the way that a logic analyzer captures data.
This mode is useful when you are looking for a particular set of ones and
zeros on a computer bus or control lines. You determine which channels
the oscilloscope uses to form the trigger pattern. Because you can set the
voltage level that determines a logic 1 or a logic 0, any logic family that
you are probing can be captured.
There are two types of logic triggering: Pattern and State. The difference
between pattern and state triggering modes is that state triggering uses
one of the oscilloscope channels as a clock.
Use pattern triggering to trigger the oscilloscope using more than one
channel as the trigger source. You can also use pattern triggering to trigger
on a pulse of a given width.
The Pattern Trigger Mode identifies a trigger condition by looking for a
specified pattern. A pattern is a logical combination of the channels. Each
channel can have a value of High (H), Low (L) or Don't Care (X). A value
is considered a High when your waveform's voltage level is greater than its
trigger level, and a Low when the voltage level is less than its trigger level.
If a channel is set to Don't Care, it is not used as part of the pattern
criteria.
One additional qualifying condition determines when the oscilloscope
triggers once the pattern is found. The :PATTern:CONDition command has
five possible ways to qualify the trigger:
Entered The oscilloscope will trigger on the edge of the source that makes the
pattern true.
Exited The oscilloscope will trigger on the edge of the source that makes the
pattern false.
Present > The oscilloscope will trigger when the pattern is present for greater than
the time that you specify. An additional parameter allows the oscilloscope
to trigger when the pattern goes away or when the time expires.
Present < The oscilloscope will trigger when the pattern is present for less than the
time that you specify.
Range The oscilloscope will trigger on the edge of the waveform that makes the
pattern invalid as long as the pattern is present within the range of times
that you specify.
Available trigger conditioning includes HOLDoff and HYSTeresis (Noise
Reject).