Andy Neil, you are absolutely true. Just after i send my last 2 posts last late night, if have again check every thing in my software and hardware and found a option which forces DSR, DTR etc to react automatically. So, i corrected the option and both signals are working transparently. So, problem is solved.
However, I like to discuss more about what could be done if we only have TX and RX pins in PC and we want to extract signals from it.

Thanks!