Trigger Controls
TDS3000 Series User Manual
3–57
Normal and Auto Mode. Use Normal trigger mode when you want to
trigger only on a valid event. Use Auto trigger mode when you want
the acquisition to occur, even when there is not a valid trigger event.
Also choose Auto when you want a rolling waveform, with no
trigger, at the slower time base settings. See page 3–32 for more
information about roll mode.
External Trigger. Two-channel oscilloscopes have an external trigger
input. The trigger level range for the EXT setting is –0.8 V to
+0.8 V. The trigger level range for the EXT/10 setting is –8 V to
+8 V.
For best external trigger performance, apply a square-wave signal
with amplitude greater than the specified minimum level range and
with well-defined transitions.
Four-channel oscilloscopes do not have a separate external trigger
input; however, you can use any of the four channels as your trigger
source.