急急急！！！高手请进！！！如何对串口的Dtr或Rts端口进行置位或复位？

[luxiaoban]

因为项目要和下位机通讯，是无线的，要对串口的Dtr或Rts端口进行置位或复位？

本人用的mscomm和spcomm控件都没有这个属性，请问有没有API函数可以对串口

的Dtr或Rts端口进行置位或复位？分数可以再加，

[luxiaoban]

高手真的不多吗？

[zhh_hf]

1. SetCommState函数,例子可以参考：http://www.csdn.net/expert/topic/244/244418.shtm

2.Moxa多串口卡的 api232.dll, 支持Moxa卡和普通串口，挺好用(如要，我可EM给你）

[NowCan]

EscapeCommFunction

The EscapeCommFunction function directs a specified communications device to perform an extended function.

BOOL EscapeCommFunction(
HANDLE hFile, // handle to communications device
DWORD dwFunc // extended function to perform
);

Parameters
hFile
Handle to the communications device. The CreateFile function returns this handle.
dwFunc
Specifies the code of the extended function to perform. This parameter can be one of the following values: Value Meaning
CLRDTR Clears the DTR (data-terminal-ready) signal.
CLRRTS Clears the RTS (request-to-send) signal.
SETDTR Sends the DTR (data-terminal-ready) signal.
SETRTS Sends the RTS (request-to-send) 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.
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. Note that this extended function does not flush data that has not been transmitted.
CLRBREAK Restores character transmission and places the transmission line in a nonbreak state. The CLRBREAK extended function code is identical to the ClearCommBreak function.


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
Windows CE: Windows CE supports the following additional flags for the dwFunc parameter:

SETIR
Sets the serial port in IR mode.
CLRIR
Sets port into normal serial mode.

[cmpp]

我来学习一下！