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标题: 用MSCOMM控件向串口发送AT指令并得到GSM MODEM的返回信息 [打印本页]

作者: dxmkaifa 时间: 2014-6-24 11:16
标题: 用MSCOMM控件向串口发送AT指令并得到GSM MODEM的返回信息
奇怪的AT指令
计算机连了一个wAVECOM的GSM MODEM,拟用MSCOMM控件向串口发送AT指令并得到GSM MODEM的返回信息。
代码如下：

　　LOCAL aVzifua as String

thisform.mycomm.portOpen=.T.
      thisform.mycomm.input
      thisform.mycomm.InBufferCount = 0
*!*          thisform.mycomm.Output = [AT] + CHR(13)
      thisform.mycomm.Output = CREATEBINARY([AT] + CHR(13))
*!*          thisform.mycomm.Output = CREATEBINARY([AT]) + CHR(13)
            nVsj=SECONDS()+5

      DO  While  SECONDS() <=nVsj

         If thisform.mycomm.InBufferCount $amp;>amp;$nbsp;0
            aVzifua =thisform.mycomm.Input
         ENDIF

      ENDDO

thisform.text1.Value=aVzifua
thisform.mycomm.portOpen=.F.

运行后总是得不到返回信息。后来装了一个监视串口信息的serial monitor软件,发现这段代码总是要运行两次，端口才能返回“OK”，但我的文本框中两次都显示不出任何字符。

特请高手赐教：
1.为什么要运行两次才能“OK”？
2.如何得到返回信息

serial monitor给出的串口信息如下：

Read:
Port opened

Baud rate set to 9600

StopBits: 1 stop bit, Parity: No parity, WordLength: 8

Port closed

Port opened

Baud rate set to 9600

StopBits: 1 stop bit, Parity: No parity, WordLength: 8
0D 0A 4F 4B 0D 0A    ..OK..
Port closed

Write:
Port opened

Baud rate set to 9600

StopBits: 1 stop bit, Parity: No parity, WordLength: 8
41 54 0D    AT.
Port closed

Port opened

Baud rate set to 9600

StopBits: 1 stop bit, Parity: No parity, WordLength: 8
41 54 0D    AT.
Port closed

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