The SCPI specifications define a standard error reporting scheme, Error/Event Queue. This is a FIFO (First In First Out) queue, which records errors and events. The maximum number of errors/events that the PWX can record is 255. Each error/event can be read with the SYSTem:ERRor query.
The response to this query contains a numeric part (error/event number) and a textual description, such as:
-222,"Data out of range"
The error/event queue is empty when the *CLS common command is sent, when the last item in the queue is read, and when the PWX is turned on. When the error/event queue is empty, the query returns the following:
Displaying communication errors
The PWX has a debug trace function. The oldest item among the errors and events (if they are present) can be displayed on the PWX. This function is convenient when you debug your remote applications.
While an error/event item is displayed on the panel, the normal voltmeter and ammeter are disabled.
If the error/event queue is empty, the debug trace function does not display any errors. Sending the *CLS command clears the communication error display.
If in local mode, the debug trace function is temporarily disabled.
The communication error display can be enabled or disabled with the SYSTem:ERRor:TRACe command.