EscapeCommFunction

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4/8/2010

This function directs a specified communication device to perform an extended function.

Syntax

BOOL EscapeCommFunction(
  HANDLE hFile,
  DWORD dwFunc
);

hFile
[in] Handle to the communication device.

The CreateFile function returns this handle.

dwFunc
[in] Specifies the extended function code to perform. The following table shows possible values.

Value	Description
CLRBREAK	Restores character transmission and places the transmission line in a nonbreak state. The CLRBREAK extended function code is identical to the ClearCommBreak function.
CLRDTR	Clears the data-terminal-ready (DTR) signal.
CLRIR	Sets port to normal serial mode. This value is specific to Windows Embedded CE.
CLRRTS	Clears the request-to-send (RTS) signal.
SETBREAK	Suspends character transmission and places the transmission line in a break state until the ClearCommBreak function is called (or EscapeCommFunction is called with the CLRBREAK extended function code). The SETBREAK extended function code is identical to the SetCommBreak function. This extended function does not flush data that has not been transmitted.
SETDTR	Sends the DTR signal.
SETIR	Sets the serial port to infrared (IR) mode. This value is specific to Windows Embedded CE.
SETRTS	Sends the RTS signal.
SETXOFF	Causes transmission to act as if an XOFF character has been received.
SETXON	Causes transmission to act as if an XON character has been received.

Nonzero indicates success. Zero indicates failure. To obtain extended error data, call the GetLastError function.

Header	winbase.h
Library	Serdev.lib
Windows Embedded CE	Windows CE 2.10 and later
Windows Mobile	Windows Mobile Version 5.0 and later