Energy Meter Manual

<Toc> <Ind> < 6. Modbus/TCP Communication Protocol>
6-15
IM 77C01E01-10E
‘Create sending data
strSendData = "123400000006020300000002" ‘Sending command character string
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Number of D registers (0002:2)
D register start number (0000:D0001)
Function code(03:Reads data from multiple D registers)
Station number of PR300 (02:Station 02)
Number of sending data bytes after station number (0006:6 bytes)
Protocol ID(0000:Fixed)
Transaction ID(1234:Arbitrary 2-byte value)
‘Text → Binary change
For iCount = 1 To 12
strCher = “&H” + Mid(strSendData, 2 * iCount - 1, 2)
‘Fetch 2 characters and change
them into hexadecimal notation.
binChrs(iCount - 1) = CByte(Val(strCher)) ‘ Change them into numerical values.
Next iCount
‘
‘Send
Winsock1.SendData binChrs ‘Send command
‘
End Sub
‘=====================================================================
Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)
‘Receive data from PR300 and cut connection with PR300.
‘
Dim binData() As Byte
Dim iCount As Integer
Dim strCher As String
‘Receive data
Winsock1.GetData binData ‘Receive command
‘
‘Binary change → Text
For iCount = 0 To bytesTotal -1
strCher = Right(Hex(binData(iCount)), 2) ‘Change every byte into a
character string.
If Len(strCher) = 1 Then
strReceive = strReceive + “0” + Mid(strCher, 1, 1)
‘Add 0 if it becomes one
character after change
Else
strReceive = strReceive + strCher
End If
Next iCount
‘
‘Cut TCP connection
Winsock1.Close
‘
End Sub