Event Queues & Displays - Keysight X-Series Manual

Overview of Instrument Messaging System
Event Queues & Displays
Event Queues & Displays
Events are logged into queues. Each source of control has its own queue. Thus
there is a Front Panel queue, a SCPI GPIB queue, a SCPI LAN queue, and so on.
Each remote queue is queried separately via its own interface.
The Front Panel queue may be viewed in two ways, via the Status or History
lists, as described in
Error events generated by one interface may only be queried over that
interface; for example, you cannot query GPIB errors from the LAN queue.
Note that Conditions are logged in the queues as pairs of Events: a Detected
Event and a corresponding Cleared Event.
Table 1-2 Event Queue & Display Types
Front Panel A-Series: Messages can be viewed by pressing System, Show Errors, Status.
Status (Current
B-Series: Displayed as a list in the Current Conditions tab of the
Conditions)
The Status/Current Conditions list shows existing conditions.
When an event is caused by a command sent over a remote interface, the resulting messages are
logged in the queue for that interface. For convenience, such Events are also logged in the Front
Panel queue.
Front Panel Event A-Series: Messages can be viewed by pressing System, Show Errors, History.
History
B-Series: Displayed as a list in the History tab of the
The History list shows all the events that have occurred since the instrument was turned on, up to a
maximum of 100 messages.
When an error situation is caused by a command sent 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.
Remote When an error event is caused by a command sent over a remote interface, the resulting messages
interfaces are output to the queue for that interface. To return an error, you must query the queue for that
interface.
An error event that is caused by a front panel action is not reported to any remote interface queue.
However, a status condition is usually caused by an internal event that is not related to a particular
interface, so the Detected/Cleared Events for status conditions are reported to all the queues.
Table 1-3 Characteristics of the Event Queues
Characteristic Front-Panel Status
Capacity (maximum 100
number of messages)
Overflow Handling Circular (rotating).
Drops oldest message as
new message comes in.
Instrument Messages
Table 1-2 below.
Status
Front-Panel History
100
Circular (rotating).
Drops oldest message as
new message comes in.
Status Dialog.
Dialog.
Remote Interfaces (GPIB/LAN)
100
Linear, first-in/first-out.
Replaces newest message with:
–350, Queue overflow
30