FYI, assuming you're using the built-in 232 port on your R1, there are a couple of other options for troubleshooting.
1) Don't forget the 232 LED on the SNAP-PAC-R1 (or -R2) itself. That will blink when there's data.
2) There's an option in the memory map to turn on logging of data to/from that port. You'll get a file that looks like this:
From my "ser:" comm handle, I was sending "testing testing 1234" -- the O before each letter here = "Out" (you'll see an "I" before "Incoming" data).
This file is generated by the PAC in the file area, I like to use Firefox to browse to that file and easily look at it:
Here's the place in PAC Manager where you can turn this handy feature on. Be sure to turn it off when you're done troubleshooting, because it does require resources on your SNAP-PAC you'd rather use for other things:
Hope that helps!