你所说的控制RTS为高电平实际意义是什么? 给出几个:1。DISABLE Disables the RTS line when the device is opened and leaves it disabled. 2。ENABLE Enables the RTS line when the device is opened and leaves it on. 3。HANDSHAKE Enables RTS handshaking. The driver raises the RTS line when the "type-ahead" (input) buffer is less than one-half full and lowers the RTS line when the buffer is more than three-quarters full. If handshaking is enabled, it is an error for the application to adjust the line by using the EscapeCommFunction function. 4。TOGGLE Specifies that the RTS line will be high if bytes are available for transmission. After all buffered bytes have been sent, the RTS line will be low.
大家还有什么好主意吗?
给出几个:1。DISABLE Disables the RTS line when the device is opened and leaves it disabled.
2。ENABLE Enables the RTS line when the device is opened and leaves it on.
3。HANDSHAKE Enables RTS handshaking. The driver raises the RTS line when the "type-ahead" (input) buffer is less than one-half full and lowers the RTS line when the buffer is more than three-quarters full. If handshaking is enabled, it is an error for the application to adjust the line by using the EscapeCommFunction function.
4。TOGGLE Specifies that the RTS line will be high if bytes are available for transmission. After all buffered bytes have been sent, the RTS line will be low.
1.DISABLE=0
2.ENABLE=1
3.HANDSHAKE=2
4.TOGGLE=3
控制RTS的方法是:DCB.Flags的第1个字节
1.DISABLE=0
2.ENABLE=1
3.HANDSHAKE=2
4.TOGGLE=3
dcb:tdcb;
begin
dcb.flags:=dcb or $1000;
//dcb.flags占4个字节,用or来改变第个1字节的值
end;
以前用Async32,但现在这控件好像不能用了。另,什么“DCB在DELPHI里少了很多的数据成员”我就不懂了。