4-10 Edit Menu
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eZ-Analyst
Continued from page 4-6
Post-
Trigger
Selecting the
“Post-Trigger”
icon button (
arrow will point right
) instructs the
system to skip a specified percentage of data [a specified percent of the frame
size] after the
start of trigger event
. If we selected “Post-Trigger” and entered
10.00 in the percent box, we would see 10% of the data skipped, in relation to
frame size.
Beep
Sound
If desired, check a box so a “beep” will sound when the
Trigger is Ready
, or when
the system has
Triggered
. If rapid triggering/acquiring data events are taking
place in succession, then the beep sound may become erratic.
Select
Free Run
from the Analyzer Tab’s Trigger Panel if you want to
measure data in a
continuous or Scope mode manner
[from an active
system].
To capture
transient data
, go to the Configuration dialog found under the
Edit menu and on the Analyzer tab select
Input Channel
and specify the
applicable channel and conditions.
Trigger-related items [in the
Analyzer Tab
or
Recording Setup Tab
]
being
locked-out indicates that the current mode is for
playback operation
. If
so, perform the following:
(1) close the Configuration Window
(2) select “Measurement Mode” from the Task pull-down menu
(3) open the Configuration window
Capturing Transient Data
Setting
eZ-Analyst
to trigger on an Input Channel captures transient data when the
associated parameters are correctly specified. The following sections discuss the associate
parameter and how they apply to a signal such as an impact hammer striking an object. The
signal show is from an accelerometer located in the hammer’s head.
Set Trigger level
:
The first and most important parameter is the trigger level. This parameter specifies the level
in which the signal must pass through in order for an acquisition process to begin. An ideal
level will assure that the signal is well above any noise or erroneous movement that will cause
a trigger. An ideal level will also assure that the level is not above the maximum output of
the signal source. Violating these ideal conditions can result in either a premature trigger or
no triggering at all. For example, if a signal has a noise floor of 0.5 volts and the trigger level
is set to 0.2 volts the acquisition will always trigger for obvious reasons. Conversely, if the
maximum signal output is 5.0 volts and the trigger is set to 5.5 volts the acquisition will never
trigger.
