Triggering on Waveforms
TDS 500B, TDS 600B, & TDS 700A User Manual
3–77
When you select the pulse class Runt, the oscilloscope will trigger on a short
pulse that crosses one threshold but fails to cross a second threshold before
recrossing the first. To set up for runt triggering, do the following procedures.
Select Runt Triggering. Press TRIGGER MENU ➞ Type (main) ➞ Pulse
(pop-up) ➞ Class (main) ➞ Runt (pop-up). (See Figure 3–45.)
Select the Source. To specify which channel becomes the pulse trigger source:
Press TRIGGER MENU ➞ Type (main) ➞ Pulse (pop-up) ➞
Source (main) ➞ Ch1, Ch2, Ch3, or Ch4 (side). The source selected becomes
the trigger source for all four trigger classes.
Select the Polarity. To specify the direction of the runt pulse:
Press TRIGGER MENU ➞ Type (main) ➞ Pulse (pop-up) ➞ Class (main) ➞
Runt (pop-up) ➞ Polarity (main) ➞ Positive, Negative, or Either (side).
Positive looks for positive-going runt pulses.
Negative looks for negative-going runt pulses.
Either looks for both positive and negative runt pulses.
Set to Trig When. To determine how wide a runt pulse the oscilloscope will
trigger on:
1. Press TRIGGER MENU ➞ Type (main) ➞ Pulse (pop-up) ➞
Class (main) ➞ Runt (pop-up) ➞ Trig When (main).
2. Press Occurs to trigger on all runt pulses regardless of width.
3. Press Runt is Wider Than (side) to trigger only on runt pulses that exceed
the width you set. Enter the width using the general purpose knob or keypad.
To Trigger on a Runt Pulse