Hi, I'm about 3 days into my LabVIEW programming, so this is likely a very basic question... I am interfacing to a small embedded system that has UDP capability on it. The device accepts an incoming command (over UDP), then sends back a response that could be multiple lines of ascii. The last line is a 1-character packet with that byte being 0x00. Referring to my VI (attached image), everything works except that the string indicator used to display the multi-line response will only show one line at a time. Each time a new line comes in, the previous one is erased. Note that I do not have "Limit to Single Line" checked for that string indicator. The target is sending \r\n (verified with Wireshark), so I'm confused. Any suggestions? UPDATE1: if I change to "Hex Display" mode, it does show the 0D0A at the end of each packet.

All you need to do is swap the inputs to the concatenate operation so the new data is appended to the end instead of the beginning. Also the =0 is pointless. Just show the initializer terminal and initialize with an empty string: ... and it this is the toplevel VI, just do a global initialization at the feedback node as follows. The shift register solution would look as follows. same difference!

LabVIEW

UDP Read data-out feeds into string indicator but won't show multiple lines.

Solved!

Author

Ok I rewrote my original block using the shift register as both of you guys suggested (see attachment). It works the same and it's visually less complex, but quite honestly my earlier implementation with the loopback on the string concatenation makes more sense to me.

Being less than a week into LabVIEW, I just need to study this for a while.

Thanks much for the help.