Opening a Port (Windows CE 5.0)
Call the CreateFile function to open a serial port.
Because hardware vendors and device driver developers can give any name to a port, an application should list the available ports and enable users to specify the port to open.
If a port does not exist, CreateFile returns ERROR_FILE_NOT_FOUND, and users should be notified the port is not available.
To open a serial port
Insert a colon after the communication port pointed to with the first parameter, lpzPortName.
For example, specify COM1: as the communication port.
Specify zero in the dwShareMode parameter unless you a supported driver that allows multiple opens.
Only one device can perform read/write or any operation that changes the behavior of the port. Other applications can perform operations such as port monitoring or controlling line status.
Specify OPEN_EXISTING in the dwCreationDisposition parameter.
This flag is required.
Specify zero in the dwFlagsAndAttributes parameter.
Windows CE supports only nonoverlapped I/O.
The following code example shows how to open a serial communications port.
// Open the serial port.
hPort = CreateFile (lpszPortName, // Pointer to the name of the port
GENERIC_READ | GENERIC_WRITE,
// Access (read-write) mode
0, // Share mode
NULL, // Pointer to the security attribute
OPEN_EXISTING,// How to open the serial port
0, // Port attributes
NULL); // Handle to port with attribute
// to copy
Before writing to or reading from a port, configure the port.
When an application opens a port, it uses the default configuration settings, which might not be suitable for the device at the other end of the connection.
See Also
Programming Serial Connections
Send Feedback on this topic to the authors