Serial Port Packed Message Programing

Emc2 · 2014-07-05T17:22:33+00:00

Nawaombeni anayeweza tafadhari. I have the Manual of Programming protocol, but when I write code vb.net returns error message. The following is the table structure of bytes array Collapse | Copy Code position 1 2 3 4 5 6 7 8 Name SOH LEN SEQ CMD DATA Post-amble BCC ETX Lenth/bytes 1 1 1 1 0-200 1 4 1 Value (01h) (20h-FFh) (20h-FFh) (20h-FFh) (20h-FFh) (05h) (30h-3Fh) (03h) Abbreviations: SOH- (Start Of Heading) start of packed message LEN- total number of bytes from position 2 to position 6, plus fixed offset of 20h. SEQ- serial number of packet. SLAVE puts the same SEQ in the reply message. In case when SLAVE receives a message with the same SEQand CMD like the last correctly received message, the device ignores the message and repeats the last packet sent to the HOST. CMD code of command DATA- data, according to the command. If there is no data, the length field is zero. BCC control sum(0000h-FFFFh). Sum of data bytes from position 2 to position 6. The control sum is transferred in ASCІІ type (12АВ is transferred as 31h 32h 3Аh 3Вh). ETX (End of TeXt) end of packed message. Codes sample: Collapse | Copy Code Public Class Form1 Private WithEvents sp As System.IO.Ports.SerialPort Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load For Each y As String In System.IO.Ports.SerialPort.GetPortNames Me.ComboBox1.Items.Add(y) Next sp = New IO.Ports.SerialPort("COM4") sp.StopBits = IO.Ports.StopBits.One sp.BaudRate = 9600 sp.DataBits = 8 sp.Parity = IO.Ports.Parity.None sp.Handshake = IO.Ports.Handshake.None sp.Open() Dim by As Byte = &H20 ' MsgBox(&H20) End Sub Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Try Dim By(9) As Byte By(0) = 1 By(1) = &H2 + &H20 By(2) = &H58 By(3) = &H45 By(4) = &H5 Dim S As String = Hex(&H58 Xor &H45) ' MsgBox(S) By(5) = &H30 By(6) = &H30 By(7) = &H31 By(8) = &H3D By(9) = &H3 sp.Write(By, 0, By.Length - 1) ' MsgBox(sp.ReadByte) Catch ex As Exception MsgBox(ex.Message) End Try End Sub Private Sub sp_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles sp.DataReceived Dim rec As System.IO.Ports.SerialPort = sender MsgBox(Hex(rec.ReadByte)) End Sub End Class

Thread starter Emc2
Start date Jul 5, 2014

Emc2

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Serial Port Packed Message Programing

Emc2

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