I'm not the best in serial comms but it appears to me you've got the HSERIN command incorrectly formatted.

I also think you haven't declared the ser variables.

I also think you've got code that's over 7 years old. I wonder why it's important to fix now?

We need to know what chip you're using, what version of PBP you're using and what you've done to try and fix the problem.

I think when they say the output is in ASCII you have to use a table to decode output. According to this link http://www.asciitable.com/for the output to be say 25 you'd have an output like 50,53 in decimal or 32, 35 hex. So you need to read the book on how to make that display the correct numbers.

I hope I haven't led you astray.