307
Triggering on a Runt Pulse
Use this procedure to detect and trigger on a runt pulse. The instrument can look for positive or negative
runt pulses. These pulses can also be qualified by time or by the logical state of other channels.
Select runt triggering
1.
Push the front-panel ADVANCED button.
2.
On the Trigger Setup control window, select the A Event
tab.
3.
Click Runt.
Select the source
4.
To specify which channel becomes the pulse trigger
source, click Source and select the source from the list.
Select the polarity
5.
Select a Polarity value to specify the direction of the runt
pulse. Triggering occurs at the point the pulse returns over
the first threshold without crossing the second threshold
level. The polarity selected in the Polarity window
determines the order that the threshold must be crossed for a
runt trigger to occur:
Pos looks at positive-going pulses. The lower threshold
must be first crossed going positive, then recrossed going
negative without the upper threshold being crossed at all.
Neg looks at negative-going pulses. The upper threshold
must be first crossed going negative, then recrossed going
positive without the lower threshold being crossed at all.
Either looks at both positive and negative pulses. Either one
of the thresholds must be first crossed going in either
direction, then recrossed going in the opposite direction
without the other threshold being crossed at all.
For all three polarity settings, triggering occurs at the point the
runt pulse recrosses its first threshold.
Qualify the runt trigger
6.
To qualify the runt pulse trigger, click Trigger When Runt,
and select from the list:
Occurs triggers on all runt pulses.
Wider triggers only on runt pulses that exceed the minimum
width you set. Enter the Width using the multipurpose knob
or pop-up keypad.
Logic triggers on a logic-qualified runt pulse. When the
instrument detects that a runt has occurred, it checks the
logical state of two other available channels and triggers
only if their conditions are met. Each channel can have a
value of high (H), low (L), or "don't care" (X). A value is
considered high if the channel input voltage is greater than
Summary of Contents for TDS5000B Series
Page 36: ...36 AFTDS Differential Signal Adapter...
Page 280: ...280 Blackman Harris window...
