Is your device sending the data actually sending data in response to the "Hello World" request you are sending? Or is it just sending data continuously?
Your VI only runs once and only does something if you happened to have made the Start button True before you ran it. Since you are configuring the port inside that case structure, you are emptying the buffer before you write the Hello World and then reading the response. If the device happens to be sending data continuously, then when you open and configure the serial port, you might just have happened to do it in the middle of a packet of data being sent.
Other things weird, what is going on with the search/split string? You don't seem to be searching on anything since you have nothing wired to the Search String input. You just have the Offset of 8. Actually, I don't think your VI is even suppose to run because the Search String input is a required input according to LabVIEW help.
So you are reading 32 bytes of data. What does that data look like? You seem to be splitting put the 32 bytes you just received into 4 groups of 8. However, you only read 32, If you have 32 bytes of actual data, then you never read the termination character that you enabled which would be the 33 byte.
What does "pulsing LabVIEW" mean?
