modbus与plc通讯 vb程序caoxi

该程序可以实现实时数据采集显示，以及能对寄存器进行设置。

程序很简单，想用的可以完善，现在只能实时采集显示一个地址的数据，只要修改一下，就可以实时采集多个地址的数据。

现在也只能一次对一个寄存器进行设置，也可以更加完善。

下面是运行界面，采集的模块的地址为75，是一个温湿度采集模块。

有3个寄存器，显示的数据上是温度，湿度，露点温度。

modbus
Private Sub Command1_Click() '设置按钮
Dim bisend() As Byte
Dim crc
Dim btLoCRC As Byte, btHiCRC As Byte
Dim Data As Integer
If MSComm1.PortOpen = True Then
If Combo5.ListIndex = 0 Then
ReDim bisend(7) '重新定义数组长度
bisend(0) = "&h" + Hex(V al(Text1.Text)) '地址码
bisend(1) = "&h" + Hex(3) '功能码读寄存器
bisend(2) = "&h" + Hex(0) '起始地址高位
bisend(3) = "&h" + Hex(0) '起始地址低位
bisend(4) = "&h" + Hex(0) '寄存器个数高位
bisend(5) = "&h" + Hex(Combo6.ListIndex + 1) '寄存器个数低位
crc = CRC16(bisend, 6, btLoCRC, btHiCRC)
bisend(6) = "&h" + Hex(btLoCRC) 'CRC高位
bisend(7) = "&h" + Hex(btHiCRC) 'CRC低位
'发送数据
MSComm1.Output = bisend
Else
ReDim bisend(10) '一次只能写一个寄存器
bisend(0) = "&h" + Hex(V al(Text1.Text)) '地址码
bisend(1) = "&h" + Hex(16) '功能码写寄存器
bisend(2) = "&h" + Hex(0) '起始地址高位
bisend(3) = "&h" + Hex(0) '起始地址低位
bisend(4) = "&h" + Hex(0) '寄存器个数高位
bisend(5) = "&h" + Hex(1) '寄存器个数低位
bisend(6) = "&h" + Hex(2) '字节数
Data = Val(Trim(Text3.Text))
bisend(7) = "&h" + Hex(Data \ 256) '要写入寄存器的值的高字节
bisend(8) = "&h" + Hex(Data Mod 256) '要写入寄存器的值的低字节
crc = CRC16(bisend, 9, btLoCRC, btHiCRC)
bisend(9) = "&h" + Hex(btLoCRC) 'CRC高位
bisend(10) = "&h" + Hex(btHiCRC) 'CRC低位
MSComm1.Output = bisend
End If
Else
MsgBox "串口没有打开"
End If
End Sub
Private Sub Command2_Click() '实时采集按钮
Timer1.Enabled = Not Timer1.Enabled '进行状态切换
End Sub
Private Sub Command3_Click()
'初始化，并打开串口
With MSComm1
If .PortOpen = False Then
.CommPort = Combo7.ListIndex + 1 '打开串口1
.Settings = Combo1.Text + "," + Combo2.Text + "," + Combo3.Text + Combo4.Text
.InputMode = 1
.InputLen = 50 '一次性从接收缓冲区中读取所有数据(8个字节为一组！！)
.InBufferCount = 0 '清空接收缓冲区
.OutBufferCount = 0 '清空发送缓冲区
.RThreshold = 5 + (Combo6.ListIndex + 1) * 2
.InBufferSize = 1024
.OutBufferSize = 1024
.PortOpen = True
Else
MsgBox "串口已经打开"
End If
End With
End Sub
Private Sub Command4_Click() '关闭串口按钮
If MSComm1.PortOpen = True Then
MSComm1.PortOpen = False
End If
End Sub
Private Sub Form_Load()
Dim i As Integer
'波特率设置
Combo1.AddItem "4800", 0 Combo1.AddItem "9600", 1 Combo1.AddItem "115200", 2
'校验位设置
Combo2.AddItem "N", 0
Combo2.AddItem "E", 1
Combo2.AddItem "O", 2
'数据位设置
Combo3.AddItem "7", 0
Combo3.AddItem "8", 1
'停止位设置
Combo4.AddItem "1", 0
Combo4.AddItem "2", 1
'功能码选择
Combo5.AddItem "读寄存器03", 0 Combo5.AddItem "写寄存器16", 1
'寄存器个数设置
Combo6.AddItem "1", 0
Combo6.AddItem "2", 1
Combo6.AddItem "3", 2
Combo6.AddItem "4", 3
Combo6.AddItem "5", 4 Combo6.AddItem "6", 5
Combo6.AddItem "7", 6
Combo6.AddItem "8", 7
Combo6.AddItem "9", 8
Combo6.AddItem "10", 9 Combo6.AddItem "11", 10 Combo6.AddItem "12", 11 Combo6.AddItem "13", 12 Combo6.AddItem "14", 13
Combo6.AddItem "15", 14
Combo6.AddItem "16", 15
Combo6.AddItem "17", 16
Combo6.AddItem "18", 17
Combo6.AddItem "19", 18
Combo6.AddItem "20", 19
Combo6.AddItem "21", 20
Combo6.AddItem "22", 21
'串口选择
Combo7.AddItem "串口1", 0
Combo7.AddItem "串口2", 1
Combo7.AddItem "串口3", 2
Combo7.AddItem "串口4", 3
'初始赋值
Combo1.ListIndex = 1
Combo2.ListIndex = 1
Combo3.ListIndex = 1
Combo4.ListIndex = 0
Combo5.ListIndex = 0
Combo6.ListIndex = 2
Combo7.ListIndex = 0
'初始化串口
End Sub
Private Sub Form_Unload(Cancel As Integer)
If MSComm1.PortOpen = True Then
MSComm1.PortOpen = False
End If
End Sub
Private Sub MSComm1_OnComm()
Dim INByte() As Byte
Dim Buf As String
Dim btLoCRC As Byte, btHiCRC As Byte
Dim Data As Integer
If mEvent = comEvReceive Then '接收到数据以后
INByte = MSComm1.Input
If INByte(1) = 3 Then '读寄存器
'CRC校验
crc = CRC16(INByte, UBound(INByte) - LBound(INByte) - 1, btLoCRC, btHiCRC)
If INByte(UBound(INByte) - 1) = btLoCRC And INByte(UBound(INByte)) = btHiCRC Then
'校验正确
'////////////////////////////////////
For i = 3 To UBound(INByte) - 2 Step 2
Data = "&h" + Hex(INByte(i)) + Hex(INByte(i + 1))
' Buf = Buf + Hex(INByte(i)) + Chr(32)
Buf = Buf + Str(Data) '转换为十进制显示
Next i
List1.AddItem Buf
End If
End If
MSComm1.InBufferCount = 0 '请缓存
End If
End Sub
Private Sub Timer1_Timer()
'定时发送命令
Dim tbisend(7) As Byte
Dim crc '定时1s
Dim btLoCRC As Byte, btHiCRC As Byte
Dim Buf As String
If MSComm1.PortOpen = True Then
tbisend(0) = "&h" + Hex(Val(Text1.Text)) '地址码
tbisend(1) = "&h" + Hex(3) '功能码读寄存器
tbisend(2) = "&h" + Hex(0) '起始地址高位
tbisend(3) = "&h" + Hex(0) '起始地址低位
tbisend(4) = "&h" + Hex(0) '寄存器个数高位
tbisend(5) = "&h" + Hex(Combo6.ListIndex + 1) '寄存器个数低位
crc = CRC16
(tbisend, 6, btLoCRC, btHiCRC)
tbisend(6) = "&h" + Hex(btLoCRC) 'CRC高位
tbisend(7) = "&h" + Hex(btHiCRC) 'CRC低位
'发送数据
MSComm1.Output = tbisend
End If
End Sub
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// ///////////////
Function CRC16(Data() As Byte, no As Integer, CRC16Lo As Byte, CRC16Hi As Byte) As String Dim CL As Byte, CH As Byte '多项式码&HA001
Dim SaveHi As Byte, SaveLo As Byte
Dim i As Integer
Dim Flag As Integer
CRC16Lo = &HFF
CRC16Hi = &HFF
CL = &H1
CH = &HA0
For i = 0 To no - 1
CRC16Lo = CRC16Lo Xor Data(i) '每一个数据与CRC寄存器进行异或
For Flag = 0 To 7
SaveHi = CRC16Hi
SaveLo = CRC16Lo
CRC16Hi = CRC16Hi \ 2 '高位右移一位
CRC16Lo = CRC16Lo \ 2 '低位右移一位
If ((SaveHi And &H1) = &H1) Then '如果高位字节最后一位为1
CRC16Lo = CRC16Lo Or &H80 '则低位字节右移后前面补1
End If '否则自动补0
If ((SaveLo And &H1) = &H1) Then '如果LSB为1，则与多项式码进行异或
CRC16Hi = CRC16Hi Xor CH
CRC16Lo = CRC16Lo Xor CL
End If
Next Flag
Next i
Dim ReturnData(1) As Byte
ReturnData(0) = CRC16Hi 'CRC高位
ReturnData(1) = CRC16Lo 'CRC低位
CRC16 = ReturnData
End Function
'CRC低位字节值表
Function GetCRCLo(ind As Long) As Byte
GetCRCLo = Choose(ind + 1, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, _
&H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, _
&H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, _
&H0, &HC1, &H81, &H40, &H1, &HC1, &H80, &H41, &H0, &HC1, _
&H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, _
&H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, _
&H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H81, &H41, _
&H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, _
&H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, _
&H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, _
&H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, _
&H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, _
&H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81,
&H40, _
&H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, _
&H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, _
&H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, _
&H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, _
&H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, _
&H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, _
&H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, _
&H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, _
&H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, _
&H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, _
&H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, _
&H80, &H41, &H0, &HC1, &H81, &H40)
End Function
'CRC高位字节值表
Function GetCRCHi(ind As Long) As Byte
GetCRCHi = Choose(ind + 1, &H0, &HC0, &HC1, &H1, &HC3, &H3, &H2, &HC2, &HC6, &H6, &H7, &HC7, &H5, &HC5, &HC4, &H4, &HCC, &HC, &HD, &HCD, _
&HF, &HCF, &HCE, &HE, &HA, &HCA, &HCB, &HB, &HC9, &H9, _
&H8, &HC8, &HD8, &H18, &H19, &HD9, &H1B, &HDB, &HDA, &H1A, _
&H1E, &HDE, &HDF, &H1F, &HDD, &H1D, &H1C, &HDC, &H14, &HD4, _
&HD5, &H15, &HD7, &H17, &H16, &HD6, &HD2, &H12, &H13, &HD3, _
&H11, &HD1, &HD0, &H10, &HF0, &H30, &H31, &HF1, &O33, &
;HF3, _
&HF2, &H32, &H36, &HF6, &HF7, &H37, &HF5, &H35, &H34, &HF4, _
&H3C, &HFC, &HFD, &H3D, &HFF, &H3F, &H3E, &HFE, &HFA, &H3A, _
&H3B, &HFB, &H39, &HF9, &HF8, &H38, &H28, &HE8, &HE9, &H29, _
&HEB, &H2B, &H2A, &HEA, &HEE, &H2E, &H2F, &HEF, &H2D, &HED, _
&HEC, &H2C, &HE4, &H24, &H25, &HE5, &H27, &HE7, &HE6, &H26, _
&H22, &HE2, &HE3, &H23, &HE1, &H21, &H20, &HE0, &HA0, &H60, _
&H61, &HA1, &H63, &HA3, &HA2, &H62, &H66, &HA6, &HA7, &H67, _
&HA5, &H65, &H64, &HA4, &H6C, &HAC, &HAD, &H6D, &HAF, &H6F, _
&H6E, &HAE, &HAA, &H6A, &H6B, &HAB, &H69, &HA9, &HA8, &H68, _
&H78, &HB8, &HB9, &H79, &HBB, &H7B, &H7A, &HBA, &HBE, &H7E, _
&H7F, &HBF, &H7D, &HBD, &HBC, &H7C, &HB4, &H74, &H75, &HB5, _
&H77, &HB7, &HB6, &H76, &H72, &HB2, &HB3, &H73, &HB1, &H71, _
&H70, &HB0, &H50, &H90, &H91, &H51, &H93, &H53, &H52, &H92, _
&H96, &H56, &H57, &H97, &H55, &H95, &H94, &H54, &H9C, &H5C, _
&H5D, &H9D, &H5F, &H9F, &H9E, &H5E, &
H5A, &H9A, &H9B, &H5B, _
&H99, &H59, &H58, &H98, &H88, &H48, &H49, &H89, &H4B, &H8B, _
&H8A, &H4A, &H4E, &H8E, &H8F, &H4F, &H8D, &H4D, &H4C, &H8C, _
&H44, &H84, &H85, &H45, &H87, &H47, &H46, &H86, &H82, &H42, _
&H43, &H83, &H41, &H81, &H80, &H40)
End Function。