Agilent 34980A  Multifunction Switch/Measure Unit *34980-90005*

Viewing Stored Alarm Data
Features and Functions 3
If an alarm occurs on a channel as it is being scanned, that channel’s
alarm status is stored in reading memory as the readings are taken, and
in a separate alarm queue. The alarm queue the only place where
non- scanned alarms (e.g. alarms during a monitor, alarms generated by
the digital modules) get logged.
You can store at least 500,000 readings in memory during
a scan. You can read the contents of reading memory at any time,
even during a scan. Reading memory is not cleared when you read it.
Each time you start a new scan, the instrument clears all readings
(including alarm data) stored in reading memory from the previous
scan.
Up to 20 alarms can be logged in the alarm queue. If more than 20
alarm events are generated, only the first 20 alarms are saved.
The alarm queue is cleared only by the *CLS (clear status) command,
when power is cycled, or by reading all alarm entries.
Front Panel Operation: View > ALARMS
From the front panel, you can view the first 20 alarms in the queue.
After turning the knob to the desired channel, press the left or right
arrow keys to view the alarm reading. The alarm queue is cleared when
you read the alarms. The annunciators indicate which alarm is being
viewed.
Remote Interface Operation: The following command reads data from the
alarm queue (one alarm event is read and cleared each time this command
is executed).
SYSTEM:ALARM?
The following is an example of an alarm stored in the alarm queue (if no
alarm data is in the queue, the command returns “0” for each field).
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2.61950000E+01 C,2004,11,21,15,30,23.000,1003,2
Reading with Units (26.195 °C)
Date (November 21, 2004)
Time (3:30:23.000 PM)
The following command retrieves scanned readings and alarm data from
reading memory (the readings are not erased).
FETCH?
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3 4 5
Agilent 34980A Mainframe User’s Guide 135
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5
Channel Number
Alarm Limit Threshold Crossed
(0 = No Alarm, 1 = LO, 2 = HI)