86 N9030B PXA Signal Analyzer Service GuideInstrument MessagesIntroductionFigure 3-1 Error Message ExampleEvent QueuesThere are several different event queues that are viewed/queried and managedseparately. Note that Conditions are logged in the queues as pairs of events: a“Detected” event and a corresponding “Cleared” event.Front Panel Status Error messages can be viewed by pressing, System, Show Errors, Status. The Statusscreen shows error conditions that currently exist. When an error event is caused by a commandsent over a remote interface, the resulting messages are logged in the queue for that interface.For convenience, they are also logged in the front panel queue.Front Panel History Error messages can be viewed by pressing, System, Show Errors, History. The Historyscreen shows all the error events that have occurred since the instrument was turned on, with amaximum of 100 messages. When an error situation is caused by a command sent over a remoteinterface, the resulting messages are logged in the queue for that interface. For convenience, theyare also logged in the front panel queue.Remote interfaces(GPIB/LAN)When an error event is caused by a command sent over a remote interface, the resultingmessages are output to the queue for that interface. To return an error, you must query the queuefor that interface. An error event that is caused by a front panel action is not reported to anyremote interface queue. However, a status condition is usually caused by an internal event that isnot related to a particular interface, so the Detected/Cleared events for status conditions arereported to all the error queues.Table 3-1 Characteristics of the Event QueuesCharacteristic Front-Panel Status Front-Panel History Remote Interfaces (GPIB/LAN)Capacity (maximumnumber of messages) 100 100 100Overflow HandlingCircular (rotating).Drops oldest error as newerror comes in.Circular (rotating).Drops oldest error as newerror comes in.Linear, first-in/first-out.Replaces newest error with:−350, Queue overflow
