主题:求助:VB RS485通讯问题
本人在编一个485通讯程序,代码如下:
Private Sub Command4_Click()
Dim bytearray(0 To 7) As Byte
MSComm1.InBufferCount = 0
MSComm1.OutBufferCount = 0
MSComm1.RThreshold = 2
bytearray(0) = &H5
bytearray(1) = &H1
bytearray(2) = &H4
bytearray(3) = &H0
MSComm1.Output = bytearray
End Sub
Private Sub Form_Load()
MSComm1.CommPort = 1
MSComm1.Settings = "9600,N,8,2"
MSComm1.InBufferSize = 1024
MSComm1.OutBufferSize = 1024
End Sub
Private Sub MSComm1_OnComm()
Dim dataread() As Byte
Dim tempdata As Variant
Dim str As String
If MSComm1.CommEvent = comEvReceive Then
tempdata = MSComm1.Input
ReDim dataread(UBound(tempdata)) As Byte
For i = 0 To UBound(tempdata)
dataread(i) = tempdata(i)
Text2 = Text2 & " " & Hex(dataread(i))
Next i
End If
End Sub
读取到的数据全是"FF FF FF FF",这是怎么回事? 我用其他调试软件发送一样的代码,得到的却是正确的。求高手帮忙解答。
Private Sub Command4_Click()
Dim bytearray(0 To 7) As Byte
MSComm1.InBufferCount = 0
MSComm1.OutBufferCount = 0
MSComm1.RThreshold = 2
bytearray(0) = &H5
bytearray(1) = &H1
bytearray(2) = &H4
bytearray(3) = &H0
MSComm1.Output = bytearray
End Sub
Private Sub Form_Load()
MSComm1.CommPort = 1
MSComm1.Settings = "9600,N,8,2"
MSComm1.InBufferSize = 1024
MSComm1.OutBufferSize = 1024
End Sub
Private Sub MSComm1_OnComm()
Dim dataread() As Byte
Dim tempdata As Variant
Dim str As String
If MSComm1.CommEvent = comEvReceive Then
tempdata = MSComm1.Input
ReDim dataread(UBound(tempdata)) As Byte
For i = 0 To UBound(tempdata)
dataread(i) = tempdata(i)
Text2 = Text2 & " " & Hex(dataread(i))
Next i
End If
End Sub
读取到的数据全是"FF FF FF FF",这是怎么回事? 我用其他调试软件发送一样的代码,得到的却是正确的。求高手帮忙解答。