I appreciate all of the help you have been giving me, as I am really learning a lot from these examples. I tried the code snippet you posted, but have gotten a longer error message (as expected, I think). I've also posted a screen shot of both the error message that I get when I call the function and also how my screen looks when I have both the Serial Monitor and the Grasshopper VB interface open at the same time. Again, I'm not sure what I'm doing wrong, and the error message looks quite confusing, but if you have any ideas, I would greatly appreciate it. Thanks again.