Winsock的循环发送命令问题，请高人指点，虚心求学

小白我编程了一个小软件是和单片机交互的，我向单片机发命令，他回给我一条回复。现在遇到是问题是，
1.如果我用循环发命令，比如FOR循环，如何能实现在接到回复后，在发下一条呢？
2.VB 的socket有没有延时机制呢？

VB code

For i = a To b
    Winsock1.SendData Data
    DoEvents
Next

或者在DataArrival件事里再发下一个数据。
VB code

Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)
    Winsock1.SendData Data
End Sub

VB code

Dim f As Boolean

Private Sub Command1_Click()
    Dim i As Integer, x As String
    Winsock1.SendData x
    For i = 1 To 20
       While Not f
          DoEvents
       Wend
       ....
       ....
       Winsock1.SendData x
       f = False
    Next
End Sub

Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)
    Dim data1 As String
    Winsock1.GetData data1
    ....
    ....
    If data1符合要求 Then f = True
    
End Sub