Fluke PM3370B Musical Instrument User Manual


 
4 - 36 HOW TO USE THE INSTRUMENT
TRIGGER MODE TRIGGERED
- Press the TB MODE key.
In the screen, the timebase mode (TB MODE) menu appears. ’auto’ is
intensified. With the "auto" mode turned on, the timebase will run free as
soon as no triggering signal is detected, in order to provide a base line.
The ’Auto’ mode works well with most signal that have frequencies of
30 Hz or higher.
- Press the softkey next to the ’auto trig single’ function to select ’trig’.
In the triggered mode, a signal is visible only when proper triggering occurs.
- Move the indicator (T-) in and out of the signal range.
In the
Analog
mode, the result is a stable and triggered signal when the indicator
is inside the signal range, and no trace appears on the screen when the indicator
is outside the signal range.
Disabling the ’auto’ function by selecting ’trig’ can be useful for displaying very low
frequency signals. The scope waits for a real trigger before the sweep starts even
if the signal frequency is very low.
In the
Digital
mode, the same criteria exist for the use of the ’auto’ function and
the ’trig’ function, but there is a difference. When the scope is in the ’trig’ mode
and triggering is lost, the acquisition will stop, but the display will reflect the last
information before the triggering stopped. This may lead you into thinking that the
scope is properly triggered because the display appears to be stable, while in fact,
you are displaying stored information only. Watch the ARM’D LED !
TB MODE
ST6737
T
T
TRIGGER
LEVEL