NetAcquire Publish/Subscribe Drag-and-Drop Telemetry Example
Remote temperature data acquisition
For the ultimate in publish/subscribe drag-and-drop display without programming, see MissionView.
NetAcquire Publish/Subscribe in combination with NetAcquire server decommutation provides the ability to develop entire telemetry applications using drag-and-drop with little or no programming. This example describes how easy it is to combine these NetAcquire system components and to utilize them within a Java application. The example uses WebGain VisualCaf, a popular Java development environment.
The NetAcquire server decommutation component provides an efficient, configurable, decommutation capability to incoming telemetry data streams. One aspect of configuring the decommutation component relates to providing a decommutation “map.” The NetAcquire Java “Telemetry Map Editor” applet is used to configure decommutation maps. This is where individual telemetry measurements are specified (see NetAcquire Decommutation). With NetAcquire Publish/Subscribe all active decommutation map telemetry measurements are automatically available to subscribing clients. In this example the telemetry measurement named “Solar Panel” is configured in the “Test1” telemetry decommutation map.
The example applet is constructed in a similar way as the Drag-and-Drop Example. However, in this example the “SubscriptionVIBAdapter” JavaBean is used instead of the “SubscriptionDataEventAdapter” JavaBean. This JavaBean is used to connect NetAcquire Publish/Subscribe subscriptions to third-party JavaBean display widgets. The icon just below the grid panel in the Form Designer represents the Subscription object. The “SubscriptionName” property is used to specify the “Solar Panel” telemetry measurement that is to be displayed.
The Meter widget is used to display values from the Solar Panel telemetry measurement. Incoming subscription values for this measurement will be represented by the Meter.
The VisualCaf Interaction Wizard is used to connect the Subscription object to the Meter object. The first wizard dialog box identifies the types of events that the Subscription object can send (a ValueChanged event).
The next wizard dialog box is used to specify the action to take after sending this event. In this example the event is sent to the Meter component’s “valueChanged()” method.
After the Interaction Wizard completes a line connects the source component to the destination component indicating the interaction relationship.
This represents an end-to-end NetAcquire Publish/Subscribe telemetry application. When it is run “Solar Panel” telemetry measurement values will be displayed in the Meter.