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Features and Functions
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Keysight 34980A Mainframe User’s Guide
Viewing Stored Alarm Data
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).