Hi,
You cannot do this with any standard API. You would have to write a
specialized device driver.
Or, perhaps, use an available device driver, such as the on from Franson --
see the links on my homepage; this might work, depending on the details of
what needs to be done. If you take a look the the Virtual Null Modem/Data
Monitor program on my homepage, I use the Franson Virtual Serial Port object
to create a virtual "Y" connector that could be used to connect and
disconnect an external application from a serial port, thus allowing
multiple devices to share it. To use this technique, you would not have to
have access to the source code for the external application that you want to
disconnect.
If you have access to the source code for the extenal app, then there are
simpler methods (simply send it a command to disconnect, by adding an
appropriate interface).
Dick
--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See
www.hardandsoftware.net for details and contact information.
