After selecting the component VIs you need and their execution order, you can then build your application. If the execution order is similar to the Application VI, you can modify the Application VI's block diagram. If your application differs significantly from the Application VI, you should build your own VI.
You should place the VIs on your block diagram in order and then wire them together using the VISA session and the error cluster parameters. You do not need to wire all inputs for all component VIs. If the default values are sufficient for your application, you do not need to wire the input terminals. For key inputs, you might want to wire the defaults anyway as a means of documenting your VI. For repeated measurements, you should place your data measurement VIs in a loop. Remember, if you place a component VI inside a loop, you must disable indexing on the VISA Session and Error cluster wires that are passed into and out of the loop.
To check for instrument errors, you should periodically call the Error Query VI. As shown in the following illustration, a user could use an oscilloscope to take frequency measurements once per second and display them to the operator. Notice that the loop terminates on three possible conditions: the operator stops the VI using a front panel control, an instrument error is detected by the Error Query VI, or an error occurs with the VISA I/O interface. If an error occurs within the loop, the Error Message VI will then display a message to the operator. The Error Message VI is similar to the General Error Handler VI, except that additional instrument-specific errors can be reported. You should use the Error Message VI after executing several instrument driver VIs to recognize and display any errors that may have occurred.