Tektronix TDS 644A Sprinkler User Manual


 
Pulse Triggering
Reference
3Ć112
H In Normal mode the oscilloscope acquires a waveform only if there
is a valid trigger. (You can force a single acquisition by pressing
FORCE TRIGGER.)
2. To change the holdoff time, press Holdoff (side). Use the general purĆ
pose knob or the keypad to enter the value in percent.
When you select the pulse class Glitch, the oscilloscope will trigger on a
pulse narrower (or wider) in width than some specified time.
Polarity & Width
This menu item lets you define the glitch in terms of polarity (positive, negaĆ
tive, or either) and width.
1. Press TRIGGER MENU Type (main) Pulse (popĆup) Polarity
and Width (main) Positive, Negative,orEither (side).
H Glitch Positive looks at positiveĆgoing pulses.
H Glitch Negative looks at negativeĆgoing pulses.
H Glitch Either looks at both positive and negative pulses.
2. Press Width (side), and set the glitch width using the general purpose
knob or keypad.
Glitch (Accept or Reject)
To specify whether to trigger on glitches or filter out glitches using the Glitch
main menu item, press TRIGGER MENU Type (main) Pulse
(popĆup) Class (main) Glitch (popĆup) Glitch (main) Accept
Glitch or Reject Glitch (side).
If you choose Accept Glitch, the oscilloscope will trigger only on pulses
narrower than the width you specified. If you select Reject Glitch, it will
trigger only on pulses wider than the specified width.
Level
To set the trigger level with the Level main menu (or the front panel trigger
LEVEL knob), press TRIGGER MENU Type (main) Pulse (popĆup)
Level (main) Level, Set to TTL, Set to ECL,orSet to 50% (side).
H If you select Level, enter a value with the general purpose knob or the
keypad.
H If you select Set to TTL, the trigger level is set to the TTL switching
threshold.
H If you select Set to ECL, the trigger level is set to the ECL switching
threshold.
Glitch Operations