Hi All,

I have a piece of code that opens a com-port in sharing mode and basically
only monitors the MSR using DosDevIOCtl calls like this:

rc = DosOpen( pszPort, &hPort, &ulAction, 0, FILE_NORMAL, 0x0001,
              OPEN_ACCESS_READWRITE | OPEN_FLAGS_NOINHERIT |
              OPEN_SHARE_DENYNONE, NULL );

rc = DosDevIOCtl( hPort, IOCTL_ASYNC, ASYNC_GETMODEMINPUT, NULL, 0, NULL,
                  &Data, ulDataLen, &ulDataLen );

Some other program does communication on that same port. Now if that other
program tries to hang up by dropping DTR, this has no effect if my program
has the comport open.
(An example of such a program is slippm.exe (or better slattach.exe))

Dropping DTR from within my program however works as expected.

Now, I'm not a serial communications guru. So it could be that I missed
something. But what?
Are there certain flags that I should use on DosOpen maybe?

==========================================================================
* Greetz from Maastricht/The Netherlands, Jeffrey
* Home: www.xs4all.nl/~jeffh    email: jeffh{at}xs4all.nl / Fido: 2:284/312.3
* PM Timer/2 - Keep an eye on that ever growing phone bill !!

---