Agilent Technologies 86121A, User Manual, Page: 88 / 240

Monitoring the Instrument 4
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21
and the most recent error is discarded. The length of
the error queue in the instrument is 30 (29 positions for
the error messages, and 1 position for the “
Queue over-
flow ” message).
The error queue is read with the SYSTEM:ERROR?
query. Executing this query reads and removes the old-
est error from the head of the queue, which opens a
position at the tail of the queue for a new error. When
all the errors have been read from the queue, subse-
quent error queries return 0,
“No error” .
For more information on reading the error queue, refer
to
“:SYSTem:ERRor?” on page 5-57 . For a list of error
messages, refer to “Error Messages” on page 8-3 .