Tektronix TDS7254 Stereo System User Manual


 
Triggering
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CSA7000 Series, TDS7000 Series, & TDS6000 Series Instruments User Manual
H Advanced triggers are a collection of trigger types that are primarily used
with digital signals to detect specific conditions. The glitch, runt, width,
transition, and timeout types trigger on unique properties of pulses that you
can specify. The pattern and state types trigger on logic combinations of
several signals. The setup/hold type triggers on the relative timing between
two signals. The advanced triggers are available on the A (Main) trigger
only.
H Comm (optional on TDS7000 Series & TDS6000 Series) is a special trigger
used on communication signals. You can use Comm triggers to test
communications signals, and Mask testing automatically uses Comm
triggers to set up signals for mask testing. You can trigger on the clock
recovered from optical (CSA7000 Series only) or electrical communication
signals.
H Serial (optional on TDS7000 Series & TDS6000 Series) is a special trigger
used on signals with serial data patterns. You can trigger on the clock
recovered from optical (CSA7000 Series only) or electrical communication
signals.
The trigger mode determines how the instrument behaves in the absence of a
trigger eve nt:
H Normal trigger mode enables the instrument to acquire a waveform only
when it is triggered. If no trigger occurs, the instrument will not acquire a
waveform, rather the last waveform record acquired remains frozen on the
display. If no last waveform exists, none is displayed. See the Normal
trigger mode part of Figure 3--22. (You can push FORCE TR IGGER, in the
Trigger control window, to force the instrument to make a single acquisi-
tion.)
H Auto trigger mode (automatic mode) enables the instrument to acquire a
waveform even if a trigger does not occur. Auto mode uses a timer that starts
after a trigger event occurs. If another trigger event is not detected before the
timer times out, the instrument forces a trigger. The length of time it waits
for a trigger event depends on the time base setting.
Trigger Modes