Trigger Mode/Coupling
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Keysight InfiniiVision 1200 X-Series and EDUX1052A/G Oscilloscopes User's Guide
123
When a trigger is found, the pre-trigger buffer contains the events that occurred
just before the trigger. Then, the oscilloscope fills the post-trigger buffer and
displays the acquisition memory. If the acquisition was initiated by
[Run/Stop]
, the
process repeats. If the acquisition was initiated by pressing
[Single]
, the acquisition
stops (and you can Pan and Zoom the waveform).
In either Auto or Normal trigger mode, a trigger may be missed if the event occurs
while the pre-trigger buffer is being filled. This may be more likely, for example,
when the horizontal scale knob is set to a slow time/div setting, such as
500 ms/div.
Trigger Indicator
The trigger indicator at the top right of the display shows whether triggers are
occurring.
In the
Auto
trigger mode, the trigger indicator can show:
•
Auto?
(flashing) — the trigger condition is not found (after the pre-trigger buffer
has filled), and forced triggers and acquisitions are occurring.
•
Auto
(not flashing) — the trigger condition is found (or the pre-trigger buffer is
being filled).
In the
Normal
trigger mode, the trigger indicator can show:
•
Trig'd?
(flashing) — the trigger condition is not found (after the pre-trigger buffer
has filled), and no acquisitions are occurring.
•
Trig'd
(not flashing) — trigger condition is found (or pre-trigger buffer is being
filled).
When the oscilloscope is not running, the trigger indicator area shows
Stop
.
When to Use Auto
Trigger Mode
The
Auto
trigger mode is appropriate when:
• Checking DC signals or signals with unknown levels or activity.
• When trigger conditions occur often enough that forced triggers are
unnecessary.
When to Use
Normal Trigger
Mode
The
Normal
trigger mode is appropriate when:
• You want to acquire only specific events specified by the trigger settings.
• Triggering on an infrequent signal from a serial bus (for example, I2C, SPI, CAN,
LIN, etc.) or another signal that arrives in bursts. The
Normal
trigger mode lets
you stabilize the display by preventing the oscilloscope from auto-triggering.
• Making single-shot acquisitions with the
[Single]
key.
