下面这段代码显示能连接上，但是plcVal()数组中的值是空值，请高手帮忙指导一下，谢谢。
Option Explicit
Option Base 1
Const ServerName = "OPCServer.WinCC"
Const NodeName = "QQXWIMEKRUOT2ZT"
Private objServer As OPCServer '定义OPC服务器
Private objGroup As OPCGroup '定义OPC 服务器中的组
Private objGroups As OPCGroups
Private objItems As OPCItems '定义OPC 服务器中的项目名
Dim StrItemIDs(10) As String
Dim ClientHandles(6) As Long
Dim Serverhandles() As Long
Dim i As Integer
Dim DataType(1000) As Integer
Dim errors() As Long
Dim accpath(1000) As String
Private Sub Command1_Click()
Dim plcVal() As Variant
Dim OPCCache As Integer
objGroup.SyncRead OPCCache, 3, Serverhandles, plcVal, errors
Text1.Text = plcVal(1)
Text2.Text = plcVal(2)
Text3.Text = plcVal(3)
End Sub