Model 7002Switch System Instruction Manual - Advanced Test ...

IEEE-488 Reference:STATus Subsystem5.16.7 :QUEue commands[:NEXT]?:STATus:QUEue[:NEXT]?Query Error QueueShort-formformatDefaults:stat:que?Power-Up*CLS:STATus:PRESetClears Error QueueClears Error QueueNo effectDescriptionAs error and status messages occur, they are placed into the Error Queue. This query commandis used to read those messages.The Error Queue is a first-in, first-out (FIFO) register. Every time you query the queue, the “oldest”message is read and that message is then removed from the queue. The queue will hold upto 10 messages. If the queue becomes full, the message “350, ‘Queue Overflow’” will occupythe last memory location in the register. On power-up, the Error Queue is empty. When the ErrorQueue is empty, the message “0, ‘No error’” is placed in the Error Queue.The messages in the queue are preceded by a number. Negative (-) numbers are used for SCPIdefined messages, and positive (+) numbers are used for Keithley defined messages. The messagesare listed in Table 4-1.After this command is sent and the Model 7002 is addressed to talk, the “oldest” message in thequeue is sent to the computer.Note: The :STATus:QUEue[:NEXT]? query command performs the same function as the :SYS-Tem:ERRor? query command (see System Subsystem).ProgrammingexampleThe following program will read the “oldest” message in the Error Queue:5 DIM A$ [30]10 OUTPUT 707; “:stat:que?”20 ENTER 707; A$30 PRINT A$40 ENDLine 5Line 10Line 20Line 30Increase string size to accommodate the length of the messages.Requests the “oldest” message in the queue.Addresses the Model 7002 to talk.Displays the message on the CRT.5-124