Trigger Del'd Tb - Fluke CombiScope PM3370B User Manual

FUNCTION REFERENCE

TRIGGER DEL'D TB

Description:
The Delayed Timebase has two operating modes: starts and triggered. In both
modes the main timebase must be triggered first, and the delay time must have
expired. The Del'd Time Base modes are selected in the DELAYED TIMEBASE
menu after switching the delayed timebase on.
In the "STARTS" mode, the DEL'D TB starts immediately after the DELAY time.
This is explained under DEL'D TB. When signal jitter is present, the effect will be
magnified by using the DEL'D TB. The jitter is eliminated by changing from the
'starts' to the triggered mode. The start of the DEL'D TB sweep is then 'postponed'
to the first DEL'D TB trigger after the delay time.
The triggered mode is activated in the DELAYED TIMEBASE menu by selecting
the trigger source (ch1, ch2 and ext trig). For stable triggering, the DEL'D TB
trigger level must be adjusted to a proper level. The trigger level for the Del'd Time
Base is adjusted with the
'starts' and 'trig'd'.
For more explanation of trigger functions, refer to 'TRIGGER MAIN TB' function.
For details about trigger coupling, see the appropriate section.
DEL'D TB 'starts' and
'trig'd' modes
The DEL'D TB trigger source and slope can be selected when:
- The menu is active.
- The 'trig'd' mode is selected.
control. The figure shows the difference between
DELAY
DTB START DIRECTLY AFTER DELAY TIME (STARTS)
DELAY TIME
DTB START AFTER DELAY TIME UPON TRIGGER PULSE (CH1...CH4)
DELAY
DELAY TIME
WAITING FOR TRIGGER
DTB
TRIGGER
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