进入COM端口> 10 [英] Access COM Port >10

问题描述

朋友，
我是C ++的新手.现在我在COM Port项目中工作.我有一个用于访问COM端口数据(发送和接收)的DLL文件.现在，我从COM1到COM9.但是我无法在COM10之上访问.为什么?如何解决此问题?请告诉我.
谢谢与问候
Naraayanan.

Hi Friends,
I am new for C++.Now i am working in a COM Port Project. I have a DLL File for accessing COM Port data(sending and Receiving).Now,I access COM1 to COM9.But i can''t access above COM10.Why?how can i solve this problem?please tell me.
Thanks and Regards
Naraayanan.

推荐答案

CreateFile()可用于使用文件名从"COM1"到"COM9"访问串行端口；但是，如果使用"COM10"或更高版本，则会返回消息INVALID_HANDLE_VALUE.

对于端口>如图9所示，在调用CreateFile()时指定串行端口的正确方法如下:

CreateFile() can be used to access serial ports using "COM1" through "COM9" for the name of the file; however, the message INVALID_HANDLE_VALUE is returned if you use "COM10" or greater.

For ports > 9, the correct way to specify the serial port in a call to CreateFile() is as follows:

CreateFile(
   "\\\\.\\COM10",     // address of name of the communications device
   fdwAccess,          // access (read-write) mode
   0,                  // share mode
   NULL,               // address of security descriptor
   OPEN_EXISTING,      // how to create
   0,                  // file attributes
   NULL);              // handle of file with attributes to copy

另外，请确保已实际安装要尝试访问的COM设备.您可以使用免费软件程序SIW进行验证: http://www.gtopala.com/ [

Also, be sure the COM device you are trying to access is actually installed. You can use the freeware program SIW to verify this: http://www.gtopala.com/[^]

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