Tektronix 071-0957-03, User Manual

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Trigger Controls
TDS3000B Series User Manual
3- 67
External Trigger. 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.
Alternating Trigger. Alternating trigger sequentially uses each active
channel as a trigger source, from the lowest-numbered active
channel to the highest-numbered active channel. Alternating trigger
is available in all trigger menus except for logic triggers.
Alternating trigger uses the current trigger settings to trigger on all
active channels; there is not a separate trigger setup for each
channel. Therefore, the trigger settings must be able to trigger on all
active signals in order to produce a stable triggered display. If one or
more of the source signals do not meet the trigger settings, the
oscilloscope either waits for that source channel to trigger (Normal
trigger mode) or autotriggers (Auto trigger mode).
Due to image persistence, all alternating trigger active channels may
appear to be synchronized. However, this does not mean that the
displayed signals are synchronized. Also, alternating trigger does not
use EXT, EXT/10, or Line signals as trigger sources.