Hi! What you're showing in your question is the callback function for the CamperaIP edit field. This function is called whenever you type something new into that edit field while running your app. If you're interested in storing whatever you type into this field for use in other parts of the app, you could have a property (for example, let's call the property "CameraIP") that you store the edit field value in. Then in the callback function you are showing, you could do the following:
function CameraIPEditFieldValueChanged(app, event)
In this function, the property "CameraIP" will get updated anytime you type something new into this edit field. Then in other places throughout the app, you can reference app.CameraIP to use whatever value is stored in this property.
If you want to have a starting IP address in that edit field, in your startupFcn callback you could do the following:
Whenever you run the app, your edit field will start out filled with this IP address.
If you're having trouble writing new values to this edit field, make sure the edit field component is set as "editable." You can field this option in the Component Browser in the Design View within app designer.
Hope this helps!