Remote Operation 
 
5-54  M370430-01  Rev B 
SCPI Error/Event Queue 
The error/event queue contains items that include a numerical and 
textual description of the error or event. Querying for the full 
queue item (for example, with SYSTem: ERRor [ :NEXT] ?) will 
return a response with the following syntax: 
<Error/Event Number>, “<Error/Event 
Description>;<Optional Device Dependent Info>“ 
The <Error/event_number> is a unique integer in the range 
[-32768, 32767]. All positive numbers are instrument-dependent. 
All negative numbers are reserved by the SCPI standard with 
certain standard error/ event codes described in the SCPI 1999 
standard document. The value, zero, is also reserved to indicate 
that no error or event has occurred. 
The second parameter of the full response is a quoted string 
containing an <Error/event_description> followed by optional 
<Device-dependent info> text. Each <Error/event_number> has a 
unique and fixed <Error/ event_description> associated with it. 
The maximum string length of <Error/event_description> plus 
<Device-dependent_info> is 255 characters. 
As errors and events are detected, they are placed in a queue. This 
queue is first in, first out. If the queue overflows, the last 
error/event in the queue is replaced with error: 
-350,”Queue overflow 
Any time the queue overflows, the least recent errors/events 
remain in the queue, and the most recent error/event is discarded. 
The error queue implemented in the XG/XTR is capable of holding 
4 errors. 
When the error queue is not empty the error queue bit in the Status 
register will be set. 
Querying For the Errors 
Executing a query of the event queue will respond with the oldest 
error currently on the queue. This error is removed. The response 
format is discussed in the error/event queue description section. 
Command: 
[:]SYSTem:ERRor[:EVENt]?