Instrument

The Instrument class is a subclass of Panel. Since a typical project often includes multiple instruments, the Instrument class was created to simplify the creation of instrument user interfaces. This class provides the basic functionality, leaving us to implement only the instrument-specific parts. In the Instrument class, two additional event loops run alongside the Module (and Panel) event loop. One handles the basic operations of the instruments, which appear as individual module commands.

Default Module Commands

Check Connection QUERY

Checks the connection between the instrument and the application

Check Config QUERY

Checks the parameters in the Config Group; if all variables are non-empty, it calls the Connect module command

Connect ACTION

Connects to the instrument

Disconnect ACTION

Disconnects from the instrument

Check Warnings LOG

Logs warnings from the instrument

Set Editable Configs CONFIG

Defines user-editable variables, which will then be accessible from the Instrument Menu

Poll Data PERIODIC

Called periodically when a device is connected. Perform periodic queries to display informational data on the UI. Can be disabled via Set Disable Poll Data

Define Non Instrument Actions CONFIG

Specify Interface Commands that should not be handled in Instrument Actions.vi

Disable Device CONTROL

Disables the instrument

Enable Device CONTROL

Enables the instrument

There is a separate virtual VI for each of these commands, which must be overridden when creating the instrument. All other module commands for a given instrument can be handled in Instrument Actions.vi.

Command Handling

The basic logic of the Instrument class is that it treats the interface commands defined by the instances as actions to be sent to the device. For connected instruments, these are handled by Instrument Actions.vi; if the instrument is not connected, it immediately returns an error message (Instrument is not connected. Action was not executed). If Instrument Actions.vi does not handle the received message, it also returns an error message (Unexpected Instrument Action received).

The exception to this are the interface commands listed in Define Non Instrument Actions.vi. The Instrument Core ignores these; they must be processed elsewhere (for example, in the Main Loop of a derived project).

In the Main Loop of a child VI, you must not handle (or at least send a reply to) any interface command that is not listed in Define Non Instrument Actions.vi. If you want to send a message from the Main Loop or UI Loop of a child VI to Instrument Actions.vi, you must add it as an Interface Command.

An interface has been created for the instruments, providing convenient access to all devices within a project. The Instruments Menu allows you to view device parameters (IP address, COM port, etc.) as well as logged warnings. These messages are processed by the other event loop within the Instrument.

The Instrument Menu, configured in the application’s main.vi, can be used to access and configure individual instruments. A pop-up menu can be opened by right-clicking. The instrument selected in the Instrument Menu is automatically loaded into the General View.

Connection Status Indicators

Simulated STATE

The instrument is running in simulated mode

Not Connected STATE

The UI device is not connected to the application

Connected STATE

The UI device is connected and operational

Disabled STATE

The device is disabled and will not process commands

Required Overrides

When creating a new instrument, you must override the following VIs in addition to Actor Core and Initialize Module Keys:

Check Connection.vi OVERRIDE

Implement the connection check logic for your instrument

Close Resource.vi OVERRIDE

Implement cleanup and resource release

Connect to Instrument.vi OVERRIDE

Implement the connection procedure for your instrument

Instrument Actions.vi OVERRIDE

Handle instrument-specific module commands

Set Editable Configs.vi OVERRIDE

Define which configuration variables are user-editable