Fluke PM3370B user manual Trigger DEL’D TB, Delay

FUNCTION REFERENCE 5 - 81

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 Δ control. The figure shows the difference between ‘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

DELAY DTB START DIRECTLY AFTER DELAY TIME (STARTS)

DELAY TIME

DELAY	DTB START AFTER DELAY TIME UPON TRIGGER PULSE (CH1...CH4)
	WAITING FOR TRIGGER

DELAY TIME

DTB

TRIGGER

MAT4214

The DEL’D TB trigger source and slope can be selected when:

-The menu is active.

-The ‘trig’d’ mode is selected.