VB 实时错误 28 堆栈空间溢出

下边这段代码，
Do Until MSComm1.InBufferCount = 24 '查询方式，等待接收24个字符
DoEvents
Loop
这句话没有的时候不会出现溢出，但是采到的数据每组之间隔一组0，有这句的时候会出现错误提示，这是为什么。

Private theGmj1 As myGmj.gmj

Private theGmj2 As mytu.tu

Dim num As Integer                     '采集数据的个数

Dim Data3(1000), Data4(1000), Data5(1000), Data6(1000) As Single

Dim data1(1000) As Single '采样电压数据的数值形式

Dim data2(1000) As Single

Dim filedata3(1000), filedata4(1000), filedata5(1000), filedata6(1000) As String

Dim filedata1(1000) As String

Dim filedata2(1000) As String

Dim I As Integer

Dim UX1 As Double

Dim UX2 As Double

Dim UY1 As Double

Dim UY2 As Double

Dim a1 As Variant

Dim b2 As Variant

    

Dim Buffer(3) As String '数据数组



Dim dbconn As New ADODB.Connection

Dim rs As New ADODB.Recordset





Private Sub Form_Load()                '初始化



If dbconn.State Then dbconn.Close

dbconn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + App.Path + "\data.mdb;Persist Security Info=False"



  Set theGmj1 = New myGmj.gmj

  Set theGmj2 = New mytu.tu

  MSComm1.Settings = "9600,n,8,1"     '设置通信口参数

  MSComm1.CommPort = 4                 '使用COM4

  MSComm1.PortOpen = True               '打开通信口

  MSComm1.InputLen = 6                '设置Input一次从接收缓冲读取字节数为6

  MSComm1.InputMode = 0                  '以文本方式读数据

  MSComm1.OutBufferCount = 0          '清除发送缓冲区

  MSComm1.SThreshold = 6             '设置Output一次从发送缓冲区读取字节数为6

 Cmdget2.Enabled = True

  Cmdstop3.Enabled = True

  Cmdquit.Enabled = True

  Call tabinit

 End Sub



Private Sub MSComm1_OnComm()              '串口通信，采集

 

Do Until MSComm1.InBufferCount = 24       '查询方式，等待接收24个字符

  DoEvents

  Loop



Select Case MSComm1.CommEvent '串口事件

Case comEvReceive '接收到数据



   For I = 0 To 3

   Buffer(I) = MSComm1.Input

   Select Case I

   Case 0

      UX1 = Val(Buffer(0))

      Case 1

      UX2 = Val(Buffer(1))

      Case 2

      UY1 = Val(Buffer(2))

      Case 3

      UY2 = Val(Buffer(3))

      End Select

      Next I

   

  Data3(num) = UX1

  filedata3(num) = Format$(Data3(num), "0.00")

  Text1.Text = filedata3(num)

  Data4(num) = UY1

  filedata4(num) = Format$(Data4(num), "0.00")

  Text2.Text = filedata4(num)

  Data5(num) = UY2

  filedata5(num) = Format$(Data5(num), "0.00")

  Text3.Text = filedata5(num)

  Data6(num) = UX2

  filedata6(num) = Format$(Data6(num), "0.00")

  Text4.Text = filedata6(num)

  Call theGmj1.gmj_gmj(2, a1, b2, UX1, UX2, UY1, UY2)      '调用matlab

  Call theGmj2.x3(1, g, a1, b2)

  data1(num) = a1

  filedata1(num) = Format$(data1(num), "0.00")

  Tu1.Text = filedata1(num)

  data2(num) = b2

  filedata2(num) = Format$(data2(num), "0.00")

  Tu2.Text = filedata2(num)

   MSFlexGrid1.TextMatrix(num, 1) = filedata3(num)

   MSFlexGrid1.TextMatrix(num, 2) = filedata6(num)

   MSFlexGrid1.TextMatrix(num, 3) = filedata5(num)

   MSFlexGrid1.TextMatrix(num, 4) = filedata4(num)

   MSFlexGrid1.TextMatrix(num, 5) = filedata1(num)

   MSFlexGrid1.TextMatrix(num, 6) = filedata2(num)

   

   Dim rsJin As New ADODB.Recordset

    If rsJin.State Then rsJin.Close

    rsJin.Open "select top 1 * from 数据保存", dbconn, adOpenKeyset, adLockPessimistic

    rsJin.AddNew

    rsJin.Fields("日期") = Date

    rsJin.Fields("时间") = Time

    rsJin.Fields("传感器1") = filedata3(num)

    rsJin.Fields("传感器4") = filedata6(num)

    rsJin.Fields("传感器2") = filedata5(num)

    rsJin.Fields("传感器3") = filedata4(num)

    rsJin.Fields("alpha") = filedata1(num)

    rsJin.Fields("beta") = filedata2(num)

    rsJin.Update

    Dim rs1 As New ADODB.Recordset

If rs1.State Then rs1.Close

    rs1.Open "select top 30 * from 数据保存 order by 时间 desc", dbconn, adOpenKeyset, adLockPessimistic



   num = num + 1

   If num > 199 Then Call renew

  Call draw

  Call tabinit

  MSComm1.InBufferCount = 0

End Select



End Sub



Private Sub Cmdget2_Click()           '连续采集

MSComm1.RThreshold = 1                '设置接收一个字节产生Oncomm事件

Timer1.Enabled = True                 '时钟有效

Call MSComm1_OnComm                   '串口通信

End Sub



Private Sub draw()

  Picture1.Cls

  Picture1.DrawWidth = 1

  Picture1.BackColor = QBColor(15)

  Picture1.Scale (0, 3.14)-(200, -3.14)

  Picture2.Cls

  Picture2.DrawWidth = 1

  Picture2.BackColor = QBColor(15)

  Picture2.Scale (0, 3.14)-(200, -3.14)

  

  For I = 1 To num - 1

    X1 = (I - 1): Y1 = data1(I - 1)

    X2 = I: Y2 = data1(I)

    Picture1.Line (X1, Y1)-(X2, Y2), QBColor(0)

    

    X1 = (I - 1): Y1 = data2(I - 1)

    X2 = I: Y2 = data2(I)

    Picture2.Line (X1, Y1)-(X2, Y2), QBColor(0)

  

  Next I



End Sub



Private Sub Command1_Click()

dbconn.Execute "delete from 数据保存"

End Sub



Private Sub Cmdstop3_Click()          '使时钟无效，停止采集

If MSComm1.PortOpen = True Then

MSComm1.PortOpen = False             '关闭通信口

End If

Timer1.Enabled = False

End Sub



Private Sub renew()

  If num = 0 Then Exit Sub

  MSFlexGrid1.Clear

  Picture1.Cls

  For I = 0 To num - 1

   data1(I) = 0

    data2(I) = 0

  Next I

  num = 0

  Call tabinit

End Sub



Public Sub tabinit()

MSFlexGrid1.Cols = 7

MSFlexGrid1.Rows = 200 + 1

MSFlexGrid1.Col = 0

For I = 1 To 200

MSFlexGrid1.Row = I: MSFlexGrid1.TextMatrix(I, 0) = " " + Str$(I)

Next I

 MSFlexGrid1.TextMatrix(0, 1) = "S1"

 MSFlexGrid1.TextMatrix(0, 2) = "S4"

 MSFlexGrid1.TextMatrix(0, 3) = "S2"

 MSFlexGrid1.TextMatrix(0, 4) = "S3"

 MSFlexGrid1.TextMatrix(0, 5) = "α"

 MSFlexGrid1.TextMatrix(0, 6) = "β"

End Sub



Private Sub Cmdquit_Click()                       '关闭程序

Unload Me

End Sub



Private Sub Timer1_Timer()

MSComm1.Output = MSComm1.Input

End Sub