Filter
Top Products
Pulse Triggering
TDS 620A, 640A, & 644A User Manual
If you select Set to 50%, you cause the digitizing oscilloscope to search
for the point halfway between the peaks of the trigger source signal and
set the trigger level to that point.
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 runt triggering:
1. Press TRIGGER MENU ➞ Type (main) ➞ Pulse (pop-up) ➞
Class (main) ➞ Runt (pop-up) ➞ Source (main) ➞ Ch1, Ch2, Ch3 (Ax1
on the TDS 620A & 524A), or Ch4 (Ax2 on the TDS 620A & 524A) (side).
(See Figure 3-63.)
2. Press Polarity (main) ➞ Positive, Negative, or Either (side).
3. Press Thresholds (main), and set the upper and lower thresholds for
runt detection with the side menu selections and the keypad or the gener-
al purpose knob.
Polarity
Use this menu item 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.
Runt Operation