Fluke PM6681 Error Reporting, Detecting Errors in the Queue, Read the Error/Event Queue, Example

Introduction to SCPI

Error Reporting

The counter will place a detected error in its Error Queue. This queue is a FIFO (First-In First-Out) buffer. When you read the queue, the first error will come out first, the last error last.

If the queue overflows, an overflow mes- sage is placed last in the queue, and fur- ther errors are thrown away until there is room in the queue again.

￿Detecting Errors in the Queue

Bit 2 in the Status Byte Register shows if the instrument has detected errors. It is also possible to enable this bit for Service Request on the GPIB. This can then inter- rupt the GPIB controller program when an error occurs.

￿Read the Error/Event Queue

This is done with the :SYSTem:ERRor? query.

Example:

SEND→ :SYSTem:ERRor?

READ← –100,￿“Command￿Error”

The query returns the error number fol- lowed by the error description.

￿Further description of all error numbers can be found in the Er- ror Messages chapter

0, “No error”

When errors occur and you do not read these errors, the Error Queue may over- flow. Then the instrument will overwrite the last error in the queue with the fol- lowing:

–350, “Queue overflow”

If more errors occur, they will be dis- carded.

￿Standardized Error Numbers

The instrument reports four classes of standardized errors in the Standard Event Status and in the Error/Event Queue as shown in the following table:

Error Class	Range of	Standard
	Error Num-	Event
	bers	Register
Command	–100 to	bit 5 - CME
Error
	–199
Execution	–200 to	bit 4 - EXE
Error
	–299
Device- spe-	–300 to	bit 3 - DDE
cific Error
	–399
	+100 to
	+32767
Query Error	–400 to	bit 2 -QYE
	–499

If more than one error occurred, the query will return the error that occurred first. When you read an error you will also re- move it from the queue. You can read the next error by repeating the query. When

you have read all errors the queue is empty, and the :SYSTem:ERRor? query

will return:

￿Command Error

This error shows that the instrument de- tected a syntax error.

Error Reporting 3-17