Clarification Again

I first wish to Thank You for your prompt response again. I am sending you another response to your feed-back as I had left out some
points in my earlier post.I wanted to add these point to the previous one but was not able to edit the same. I would like to inform
you that testing my program with the Hyperterminal was one of the first things I did as soon as I had this problem.I also wanted to
check if my program was communicating correctly at 19200BPS and it worked fine with the Hyperterminal.
I have tested the wiring between the TxD,Rxd and GND pins of my DB9 connector and the RJ45 connector of the PLC Port1 and they
seem to be correct. Also, my microcontroller program sends byte as they are to the PC and does not swap them. This too I was able
to find out using the Hyper-terminal. I am not able to find out exactly where I am going wrong.
I was able to communicate with the PLC using the TestComm PC utility available from the GE Fanuc web-site.This utility apparently
sends the messages in the same sequence as I have posted in my query.(They have also provided the complete source code for this
utility in VC++. I am not familiar with VC++; but I know C and C++ and from what I was able to understand from the VC++ coding,
they have sent the long break,T4 delay,the X-Attaxh/Attach Message and then T1 Delay in sequence before getting the X-Attach/
Attach Resoinse).But, still I am not able to communicate with the PLC using my microcontroller.
I hope I can get a solution to my problem soon as I would very much like to get this application running at least by this month end.

Same Problem Dude !

HI Mani,

Good to know that somebody like me is also getting screwed up in writing a device driver for a PLC. Believe it or not i have gone through all ur problems posted ans the repies by steve and other guys.

It is so similar to what i am facing, Also about the testcomm utility
it uses som APIs and dlls so hell with that but yeah i found something that they send an escape character after the attach message code i.e 1B after sending 41h.
So if u have made ne progress do let me know

But meanwhile u can contact me at [email protected]
ANd if poss gimme ur phone no !
Note mine is 91-0731-2592296 ofcourse i am in india !!
C ya buddy !!