Hi Steve, thanks for the answer!
What we were using for string terminators were definitely not HEX values of line feed (\n) and carriage return (\r). What HyperTerminal thinks its the end of the message is actually "\r\n" and this is what we had in PCo. What we ended up with was a series of streams, as in the screen capture below:
The connection was stable, but we could not understand the contents. I was also trying to use a fixed length of 255, but the streams were different in length. What you see in the above picture s a series of streams is displayed in HyperTerminal as one row.
We have another test scheduled tomorrow (the scanner is used in production currently) and we'll try to use "\0D\0A" instead. I'll keep you posted!