SetCommState
The SetCommState
function configures a communications device according to the specifications in
a device-control block (a DCB
structure). The function reinitializes all hardware and control settings, but
it does not empty output or input queues.
BOOL SetCommState(
|
HANDLE hFile, |
// handle of
communications device |
|
LPDCB lpDCB |
// address of
device-control block structure |
|
); |
|
Parameters
hFile
Identifies
the communications device. The CreateFile function returns this handle.
lpDCB
Points to a DCB structure containing the
configuration information for the specified communications device.
Return Values
If the
function succeeds, the return value is nonzero.
If the
function fails, the return value is zero. To get extended error information,
call GetLastError.
Remarks
The SetCommState
function uses a DCB
structure to specify the desired configuration. The GetCommState function returns the current
configuration.
To set only a
few members of the DCB structure, you should modify a DCB
structure that has been filled in by a call to GetCommState. This
ensures that the other members of the DCB structure have appropriate
values.
The SetCommState
function fails if the XonChar member of the DCB structure is equal to the XoffChar
member.
When SetCommState
is used to configure the 8250, the following restrictions apply to the values
for the DCB structure s ByteSize and StopBits members:
The number of data bits must be
5 to 8 bits.
The use of 5 data bits with 2
stop bits is an invalid combination, as are 6, 7, or 8 data bits with 1.5 stop
bits.
See Also