I am sometimes able to receive the data successfully where as sometimes i am not able to receive it at all.
The fact that you "sometimes" are able to receive data indicates that either your interfacing or your software is marginal.

I am not sending data at all. I only need to receive the data from an external device !

then why

setb TI

Without spending a long time perusing your code, you are stuck with a TI bit being set, how that affect a non-interrupt (a BAD ides) serial I do not know, but in a decent interrupt driven serial processing it would create havoc.

You WILL see problems as you progress with your code (less at 2400 than at higher speeds) so do yourself a favor and recode to interrupt driven.

You never answered "are you one of those that believe that RS232 is possible without a MAX232 (equivalent) ?"


Erik