Technical data

SYSTem Subsystem 5
U2751A Programmer’s Reference Guide 25
SYSTem:ERRor?
Syntax
SYSTem:ERRor?
This query returns the error number and its corresponding message string
from the instrument’s error queue. A record of up to 20 errors can be
stored in the instrument's error queue. The USB remote interface I/O
session has its own interface-specific error queue. Errors that appear in
the error queue of the I/O session cause the error.
For a complete listing of the U2751A's error messages, refer to Chapter 7,
“Error Messages” on page 47.
Remarks
• This query is only used when the user is controlling the relay using
own software.
• Errors are retrieved in first-in, first-out (FIFO) order where the first
error returned is the first error that was stored. Once you have read all
the interface-specific errors, the errors in the global error queue are
retrieved.
• If more than 20 errors have occurred, the last error stored in the queue
(the most recent error) is replaced with –350, "Queue overflow". No
additional errors are stored until you remove errors from the queue. If
no errors have occurred when you read the error queue, the instrument
responds with 0, "No error".
• Error conditions are also summarized in the Status Byte Register. For
more information on the SCPI Status System for the U2751A, refer to
Chapter 2, “SCPI Status Registers” on page 9.
• The interface-specific and global error queues are cleared by the clear
status (*CLS) command and when power is cycled. The errors are also
cleared when you read the error queue. The error queue is not cleared
by a factory reset (*RST) command.