See Also
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Call the CreateFilefunction 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, CreateFilereturns ERROR_FILE_NOT_FOUND, and users should be notified the port is not available.
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Insert a colon after the communication port pointed to with the first parameter, lpzPortName.
For example, specify COM1: as the communication port.
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Specify zero in the dwShareModeparameter unless you are using a driver that supports 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.
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Specify OPEN_EXISTING in the dwCreationDispositionparameter.
This flag is required.
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Specify zero in the dwFlagsAndAttributesparameter.
Windows Embedded CE supports only nonoverlapped I/O.
The following code example shows how to open a serial communications port.
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// 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 |
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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.