The SetCommMask function specifies a set of events to be monitored for a communications device.
BOOL SetCommMask(
HANDLE hFile, // handle to communications device
DWORD dwEvtMask // mask that identifies enabled events
);
| Value | Meaning |
|---|---|
| EV_BREAK | A break was detected on input. |
| EV_CTS | The CTS (clear-to-send) signal changed state. |
| EV_DSR | The DSR (data-set-ready) signal changed state. |
| EV_ERR | A line-status error occurred. Line-status errors are CE_FRAME, CE_OVERRUN, and CE_RXPARITY. |
| EV_RING | A ring indicator was detected. |
| EV_RLSD | The RLSD (receive-line-signal-detect) signal changed state. |
| EV_RXCHAR | A character was received and placed in the input buffer. |
| EV_RXFLAG | The event character was received and placed in the input buffer. The event character is specified in the device's DCB structure, which is applied to a serial port by using the SetCommState function. |
| EV_TXEMPTY | The last character in the output buffer was sent. |
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.
The SetCommMask function specifies the set of events that can be monitored for a particular communications resource. A handle to the communications resource can be specified in a call to the WaitCommEvent function, which waits for one of the events to occur. To get the current event mask of a communications resource, use the GetCommMask function.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winbase.h.
Import Library: Use kernel32.lib.
Communications Overview, Communication Functions, CreateFile, DCB, GetCommMask, SetCommState, WaitCommEvent