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Since these events do not occur regularly (if they occur at all), they are only recorded by ATPOL II
when they occur. Therefore when allocating capacity to the various logs and waveforms, there is no
definite way to judge how much capacity will be needed.
There are three types of recordings of swell/dip events that may be used:
Swell/Dip Event log
Swell/Dip RMS graph log
Swell/Dip waveforms.
Each of these recordings will be discussed at length in next few sections.
The fact that the ATPOL II evaluates the RMS value of every ½ cycle of every input means that no
swells or dips are ever missed and the most precise measurement of their duration is available.
If thresholds are set, swell/dip monitoring begins when consumption monitoring begins and continues
without interruption. While monitoring is in progress, asterisks , "*", appear on both ends of the bottom
line of the display. They flash on and off each second to assure you that monitoring is in progress.
When monitoring stops, you are assured that monitoring has ended by the absence of the flashing
asterisks, "*".
After you direct ATPOL II to stop monitoring, all the information remains available to you in the swell/dip
log, the RMS graph log, and the swell/dip waveform captures that are in ATPOL II. The data is
preserved even if the unit is turned off and on repeatedly. The contents of the various data logs are not
displayed on ATPOL II's display. To obtain this information, it must be uploaded from ATPOL II to your
computer using the PSM software. The data is recorded into files in a plain text format that may be
easily imported into spreadsheets, databases, and word processors. In addition, PSM has extensive
graphing and printing capabilities.
Please Note: Before you start monitoring, verify that ATPOL II's wall-charger is charging the internal
batteries. The internal batteries won't operate ATPOL II for many hours without assistance. Verify that
the red charging indicator light is shining through its hole near the DC input jack.
High-speed transients, which are independent from the power line frequency may have sufficient size
and duration to trigger a swell event. Nevertheless, their trigger points and capacities are normally set
and maintained separately from swell/dip events (see the
Monitoring High-speed Transient Events
chapter).
Swell/Dip Event Log
The swell/dip log is a compact text file. It contains the basic swell/dip event information:
Timestamp
Signal triggered
Event type (swell or dip)
Magnitude
Duration.
The
“timestamp” records the date and the time that the event began, to the nearest millisecond. The
“signal triggered” is simply the name of the signal that had was triggered, such as “V
1N
”. The
“magnitude” is the RMS of the ½ cycle that had the largest RMS level (for swells) or the smallest RMS
level (for dips). The
“duration” is how long, in milliseconds, the event lasted, starting with the first ½
cycle that exceeded the trigger threshold and ending with the first ½ cycle that did not exceed the
trigger threshold and was followed by 1 second of not passing the trigger threshold.
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