Modbus 通讯协议编程.doc

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1、Modbus通讯协议编程本人最近为了实现电脑与DeltaVFD-M变频器通讯，特意用VB6.0编了一个Modbus协议通讯软件，不过这只是一个测试版，但Modbus的ASCii协议和RTU协议都己经实现。现在将源程序上贴，希望可以帮助到有需要的朋友，谢谢！(我发现图片贴不上去)另外，假如你觉得有更好的想法，欢迎E-mail指教。附：VB6源程序OptionExplicitPrivateTextltextAsStringPrivateRTUCRCAsString'串口选择PrivateSubCombo1_Click()MSComml.CommPo

2、rt=Combol.Listindex+1EndSub'数据位改变PrivateSubCombo2_Click()CallsettingEndSub'波特率改变PrivateSubCombo3_Click()CallsettingEndSub'奇偶校验改变PrivateSubCombo4_Click()CallsettingEndSub'停止位改变PrivateSubCombo5_Click()CallsettingEndSubPrivateSubsetting()MSComml.Settings=CStr(Combo3.Text)&&CStr

3、(Combo4.Text)&"，”&CStr(Combo2.Text)_&&CStr(Combo5.Text)EndSub'打开关闭串口PrivateSubCommand1_Click()OnErrorResumeNextIfMSComml.PortOpen=FalseThenMSComml.PortOpen=TrueElseMSComml.PortOpen=FalseEndIfIfMSComml.PortOpenThen使能Commandl.Caption=”关闭串口"Combol.Enabled=FalseElseCommandl.Capt

4、ion=”打开串口”Combol.Enabled=TrueEndIfIfErrThenMsgBoxError$,48,"错误信息”ExitSubEndIfEndSub'10转16进制PrivateSubCommand2_Click(IndexAsInteger)OnErrorResumeNextText4.Text=Hex(Text3.Text)IfErrThenMsgBoxError$,48,”错误信息”ExitSubEndIfEndSubT6转10进制PrivateSubCommand3_Click()DimaAsLonga=Val(”&H

5、”&CStr(Text4.Text))Text3.Text=aEndSub'手动串口发送PrivateSubCommand4_Click()IfMSComml.PortOpen=FalseThenMsgBox”请先打开串口,”错误信息'ExitSubEndIfCallsentsubEndSub'清除接收窗PrivateSubCommand5_Click()Text2.Text=””EndSubPrivateSubCommand6_Click()UnloadMeEndSub'打开关闭按钮显示文字及combol'打开串口失败，则显示出错信息“则显示

6、出错信息PrivateSubCommand7_Click()OnErrorResumeNextDimSTPAsStringSTP=CStr(Chr(2))&**010001"&CStr(Chr(3))&n25"MSComml.Settings="9600,N,7,2”MSComml.PortOpen=TrueMSComml.Output=STPMSComml.PortOpen=FalseIfErrThen'打开串口失败，则显示出错信息MsgBoxError$,48,”错误信息"ExitSubEndIfEndSubPrivateSubComman

7、d8_Click()OnErrorResumeNextDimFWDAsStringFWD=CStr(Chr(2))&"010101"&CStr(Chr(3))&"26"MSComml.Settings=”9600,N,7,2”MSComml.PortOpen=TrueMSComml.Output=FWDMSComml.PortOpen=FalseIfErrThen'打开串口失败，则显示出错信息MsgBoxError$,48,”错误信息”ExitSubEndIfEndSubPrivateSubCommand9_Click()OnErrorResu

8、meNextDimREVAsStringREV=CStr(Chr(2))&”010201”&CStr(Chr(3))&“27”MSComml.Sett