User`s guide

6-14

Status Reporting

Error Queue

As errors are detected, they are placed in an error queue. This queue is first in,

first out. If the error queue overflows, the last error in the queue is replaced

with error 350, Queue overflow. Any time the queue overflows, the least recent

errors remain in the queue, and the most recent error is discarded. The length

of the oscilloscope’s error queue is 30 (29 positions for the error messages, and

1 position for the Queue overflow message).

The error queue is read with the SYSTEM:ERROR? query. Executing this query

reads and removes the oldest 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, subsequent error queries return 0, No error.

The error queue is cleared when:

• the instrument is powered up,

• the instrument receives the *CLS common command, or

• the last item is read from the error queue.