VB和WinCC的OPC变量交换

VB和WinCC的OPC变量交换

分别在VB和WinCC内部变量中定义了3个变量，16位Word型。

编程时，VB中的 Text1、2、3分别对应于wincc中的aa、bb、cc，

但是，当按下“写按钮”时，却是将 Text1正确写入了bb，其他没变化。

当按下“读按钮”时，却是Text2、3正确读入了aa、bb。Text1变成了空白，如附图所示。

是哪儿错了？

Option Explicit

Dim OpcSvr As OPCServer

Dim OpcGrps As OPCGroups

Dim OpcGrp As OPCGroup

Dim OpcItms As OPCItems

Dim ItemSvrHdls() As Long

Dim NumItem As Long

Dim Errors() As Long

Dim ItemIDs(3) As String

Dim DataType(1000) As Integer

Dim accPath(1000) As String

Dim CltHdls(3) As Long

Private Sub Form_Load()

Set OpcSvr = New OPCServer

OpcSvr.Connect "OPCServer.WinCC", 20160623 - 2027 '连接服务器

MsgBox "CONNECT SUCCESSFUL"

Set OpcGrps = OpcSvr.OPCGroups

Set OpcGrp = OpcGrps.Add("VBOPC")

ItemIDs(1) = "aa"

ItemIDs(2) = "bb"

ItemIDs(3) = "cc"

CltHdls(1) = 1

CltHdls(2) = 2

CltHdls(3) = 3

DataType(1) = vbVString

DataType(2) = vbVString

DataType(3) = vbVString

accPath(1) = ""

accPath(2) = ""

accPath(3) = ""

  Set OpcItms = OpcGrp.OPCItems

  OpcItms.AddItems 3, ItemIDs, CltHdls, ItemSvrHdls, Errors, DataType, accPath

End Sub

Private Sub Command3_Click() '读WinCC 中变量

Dim plcVal() As Variant

OpcGrp.SyncRead OPCCache, 3, ItemSvrHdls, plcVal, Errors

Text1.Text = plcVal(1)

Text2.Text = plcVal(2)

Text3.Text = plcVal(3)

End Sub

Private Sub Command4_Click() '写入WinCC 中

Dim plcVal(3) As Variant

plcVal(1) = Text1.Text

plcVal(2) = Text2.Text

plcVal(3) = Text3.Text

  OpcGrp.SyncWrite 3, ItemSvrHdls, plcVal, Errors

------Option explicit

option base 1'''''''少了这行

少了一行语句，估计定义变量读写顺序的吧？加上后正常了。

--------数组下标默认是从0开始，加了option base 1就从1开始。

-------Private Sub Command1_Click()

    Dim prtrun
    Dim tag0
    Dim WinCC As Object '定义wincc为对象
    Set WinCC = CreateObject("WinCC-Runtime-Project")
    prtrun = WinCC.SetValue("NewTag_1", Text1(0).Text)
    prtrun = WinCC.SetValue("NewTag_2", Text1(1).Text)
    prtrun = WinCC.SetValue("NewTag_3", Text1(2).Text)
    prtrun = WinCC.SetValue("NewTag_4", Text1(3).Text)
    prtrun = WinCC.SetValue("NewTag_5", Text1(4).Text)
    prtrun = WinCC.SetValue("NewTag_6", Text1(5).Text)
    prtrun = WinCC.SetValue("NewTag_7", Text1(6).Text)
    prtrun = WinCC.SetValue("NewTag_8", Text1(7).Text)
    '先写入一个值，再读回它,判断有没有写进去,由此来判断WINCC是不是在运行之中
    prtrun = WinCC.GetValue("NewTag_1")

    If prtrun = 111 Then
        MsgBox ("与WinCC通讯成功！")
        Set WinCC = Nothing
    Else
        MsgBox ("与WinCC通讯失败！请将WinCC设置为运行状态！")
        Set WinCC = Nothing
    End If
End Sub

感觉VB这样读写WINCC变量比较简单

代码来自http://blog.sina.com.cn/s/blog_669692a60101a7n7.html