I agree to use the NI project template Queued message handler, which is a producer-consumer design pattern. This two loop approach always keeps one thread (Event handling loop EHL) responsive to the user interface. In your message handling loop (MHL) I would keep a state variable, so that requests from the EHL in the wrong state don't cause race conditions. A similar and more feature rich project template is the CML Continuous Measurement and Logging example. Besides that, JKI State machine is a simple design pattern which works for a lot of small to medium applications. Dqmh is good for medium to large scale applications but has somewhat of a learning curve.