Agilent Technologies L4400 - Manual (Page 109)

Operating and Programming 3
L4400 User’s Guide 97
Error Conditions
Usage:
• All L4400 Series Instruments
When the L4400 instrument’s front panel ATTN LED is red, one or more
command syntax or hardware errors have been detected. A record of up
to 20 errors can be stored in the instrument’s error queue.
For a complete listing of the error messages, see the Programmer’s
Reference Help file located on the Agilent L4400 Product Reference
CD- ROM that ships with the instrument.
• A special global error queue holds all power- on and hardware- related
errors (e.g., over- temperature, Safety Interlock, etc.).
• Errors are retrieved in first- in- first- out (FIFO) order. The first error
returned is the first error that was stored. Errors are cleared as you
read them. Once you have read all of the interface- specific errors, the
errors in the global queue are retrieved.
• Errors are cleared as you read them. When you have read all errors
from the interface- specific and global error queues, the ATTN
annunciator turns off.
• If more than 20 errors have occurred, the last error stored in the
queue (the most recent error) is replaced with - 350,“Error 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”.
• The interface- specific and global error queues are cleared by the *CLS
(Clear Status) 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) or an Instrument Preset
( SYSTem:PRESet command).
The following command is used to read errors from the error queue. One
error is read per command.
SYSTem:ERRor?