I know this is an old topic, but I seem to be having the same problem. The first time I switch forms after opening the application it takes about 15 seconds to load the form. After that it takes about 500ms. Has anyone found a solution to this? Is it possible to load each form when the application boots so the operator doesn't experience the delay?
The reason for this is because on the first opening of the screen, the driver will read every value one at a time to get its type and validate it. After that it will optimize the reading. If you have a small number of items on a screen, the delay will be short and barely noticeable. There is no real work around. As a general rule, when I start up or reboot a screen, I select each page to get through those initial delays.
If you see 15 seconds I am guessing that either you have a lot of items on a screen, slow communications, or a slow PC. I rarely see more than 3 second delay.