I have found that ANYTHING for debugging using the PC is a pain in the largest muscle. You constantly want to look at your schematic/your code/the calculator/Hyperterminal etc. I do know that Mr. Gates wonderful invention claim to do may things at once, just try to let a PC driving a J1708 line do something else as well.

Abhishek,
Just visualize scoping on communication between your PC and your board using hyperterminal. Then follow Kais recommandation.

Erik