Trig - Fluke PM6690 Operator's Manual

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Speed
The Auto-function measures amplitude and
calculates trigger level rapidly, but if you aim
at higher measurement speed without having
to sacrifice the benefits of automatic trigger-
ing, then use the Auto Trig Low Freq func-
tion to set the lower frequency limit for volt-
age measurement.
If you know that the signal you are interested
in always has a frequency higher than a cer-
tain value f , then you can enter this value
low
from a value input menu. The range for f
1 Hz to 100 kHz, and the default value is
100 Hz. The higher value, the faster measure-
ment speed due to more rapid trigger level
voltage detection.
Even faster measurement speed can be
reached by setting the trigger levels manually.
See Trig below.
Follow the instructions here to change the
low-frequency limit:
Press SETTINGS ® Misc ®
–
Auto Trig Low Freq.
–
Use the UP/DOWN arrow keys or the nu-
meric input keys to change the low fre-
quency limit to be used during the trigger
level calculation, (default 100 Hz).
–
Confirm your choice and leave the SET-
TINGS menu by pressing EXIT/OK three
times.

Trig

Value input menu for entering the trigger level
manually.
Use the UP/DOWN arrow keys or the nu-
meric input keys to set the trigger level.
A blinking underscore indicates the cursor po-
sition where the next digit will appear. The
LEFT arrow key is used for correction, i.e.
deleting the position preceding the current
cursor position.
Fig. 3-9
NOTE: It is probably easier to make small ad-
justments around a fixed value by us-
is
low
ing the arrow keys for incrementation
or decrementation. Keep the keys de-
pressed for faster response
NOTE: Switching over from AUTO to MAN Trig-
ger Level is automatic if you enter a
trigger level manually.
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Auto Once
Converting "Auto" to "Fixed"
The trigger levels used by the auto trigger can
be frozen and turned into fixed trigger levels
simply by toggling the MAN/AUTO key. The
current calculated trigger level that is visible
on the display under Trig will be the new
fixed manual level. Subsequent measurements
will be considerably faster since the signal
levels are no longer monitored by the instru-
ment. You should not use this method if the
signal levels are unstable.
NOTE: You can use auto trigger on one input
and fixed trigger levels on the other.
Input Signal Conditioning
Value input menu for setting the
trigger level.
Input Amplifier 3-5