Well, you have a VI in a loop with the text SYNC DEVICE in there. This is the VI where you should add a timeout constant of 1000 to the first VI that gets called in there.
Someone obviously improved the Initialize Device.vi to get rid of the hard 5000 ms delay, which in itself is a very good idea. However this does not seem to work nicely with the Arduino Mega, apparently.
Right click on Open Serial VI and click on Open Front Panel, then go to its block diagram
Right click on Initialize VI and click on Open Front Panel, then go to its block diagram
Let me know if that helps.
Hi I have just revisited this and it now works! I am not sure what I was doing wrong before.
As a test I removed the time delay and it failed as it did, put it back in and it works again.
Thank you everybody who helped me.