🚀 go-pugleaf

Neil P. wrote:

>I use ClearCommError(hComm, &dwErrorMask, & Comstat)
>to view what is coming in the cbInQue,

Have no idea why you would use that along with overlapped i/o?
If you aren't using overlapped i/o then remove it from your ReadFile()
It should be NULL unless you are using actually using it.

>Once, I detect there is something in the que, I
>use ReadFile(hComm, inbuff, nBytes, &nBytesRead, &overlapped), I am in this
>routine upto 2 times the amount of bytes coming in, using my baudrate 9600.

So, again, I'll ask...What is the value of nBytes?  Is it 1 or 2?
If you are trying to read more bytes than are available, it will wait
for more bytes to arrive (or time out after some amount of time [10
seconds? See  GetCommTimeouts() ] ).

>So I beleive there is plenty of time so that byte can be placed in the que
>buffer.

Does ReadFile() return True or False?
If False, have you checked the value of GetLastError()?


>If the unit sending the byte responds ( in a millisecond), then how long is
>it before Windows reports to the ClearCommError or to the struct_COMSTAT
>that there is a byte waiting?  Does Windows take more than a second to place
>it on the que?

I don't know, never used it, but I'd expect it to be immediate.