A question about hardcopy GPIB remote control?

HI

    I  have implemented some basic functions.Now I want to use the remote print screen, but there are some problems：

1，use viReadToFile ，the documents are only have 4096kb

2，use viRead，Program death

    This is my VB.NET source with viReadToFile code：

 

Private Sub FSE_btnHDCP_Click(sender As Object, e As EventArgs) Handles FSE_btnHDCP.Click
             status = viVPrintf(vi, "YST:COMM:GPIB:RTER EOI" + vbCrLf, 0) '此命令更改分隔符。
        status = viVPrintf(vi, ":HCOPEV:LANG WMF" + vbCrLf, 0) '设置WMF格式        
        status = viSetAttribute(vi, VI_ATTR_TMO_VALUE, 20000) '设置超时
        status = viVPrintf(vi, ":HCOPEST1 'MMEM'" + vbCrLf, 0) '
        status = viVPrintf(vi, ":MMEM:NAME 'C:\USER\DATA\FILE.WMF'" + vbCrLf, 0) '
             status = viVPrintf(vi, ":HCOP" + vbCrLf, 0) '开始
        
        status = viVPrintf(vi, ":MMEM:MSIS 'C’" + vbCrLf, 0) '

        status = viVPrintf(vi, ":MMEM:CDIR '\USER\DATA\'" + vbCrLf, 0) '
        status = viVPrintf(vi, ":MMEMATA? 'FILE.WMF'" + vbCrLf, 0) '
        status = viRead(vi, strRes, 16, retCount)
        Dim x As Integer = Val(Mid(strRes, 2, 1))
        Dim y As Integer = Val(Mid(strRes, 3, x))
        VI_txtOUT.Text = retCount

        status = viVPrintf(vi, ":MMEM:MSIS 'C’" + vbCrLf, 0) '
        status = viVPrintf(vi, ":MMEM:CDIR '\USER\DATA\'" + vbCrLf, 0) '
        status = viVPrintf(vi, ":MMEMATA? 'FILE.WMF'" + vbCrLf, 0) '
        status = viReadToFile(vi, "D:\YouName.WMF", x + y + 2, retCount) '最大4096，且写入不覆盖。

        status = viSetAttribute(vi, VI_ATTR_TMO_VALUE, 2000) '设置超时为默认2秒
    End Sub

 

      This is my VB.NET source with viRead code：

 

     Private Sub FSE_btnHDCP_Click(sender As Object, e As EventArgs) Handles FSE_btnHDCP.Click

        status = viVPrintf(vi, "YST:COMM:GPIB:RTER EOI" + vbCrLf, 0) '此命令更改分隔符。
        status = viVPrintf(vi, ":HCOPEV:LANG WMF" + vbCrLf, 0) '设置WMF格式
        status = viSetAttribute(vi, VI_ATTR_TMO_VALUE, 20000) '设置超时
        status = viVPrintf(vi, ":HCOPEST1 'MMEM'" + vbCrLf, 0) '
        status = viVPrintf(vi, ":MMEM:NAME 'C:\USER\DATA\FILE.WMF'" + vbCrLf, 0) '
        status = viVPrintf(vi, ":HCOP" + vbCrLf, 0) '开始
        Threading.Thread.Sleep(2000)
        status = viVPrintf(vi, ":MMEM:MSIS 'C’" + vbCrLf, 0) '

       status = viVPrintf(vi, ":MMEM:CDIR '\USER\DATA\'" + vbCrLf, 0) '
        status = viVPrintf(vi, ":MMEMATA? 'FILE.WMF'" + vbCrLf, 0) '

 

        status = viRead(vi, strRes, 16, retCount)
        Dim x As Integer = Val(Mid(strRes, 2, 1))
        Dim y As Integer = Val(Mid(strRes, 3, x))
        VI_txtOUT.Text = retCount

 

        status = viVPrintf(vi, ":MMEM:MSIS 'C’" + vbCrLf, 0) '
        status = viVPrintf(vi, ":MMEM:CDIR '\USER\DATA\'" + vbCrLf, 0) '
        status = viVPrintf(vi, ":MMEMATA? 'FILE.WMF'" + vbCrLf, 0) '
        status = viRead(vi, strRes, x + y + 2, retCount) '太长时读出为空，容易卡死
        If (status < VI_SUCCESS) Then

 

           MsgBox（" Failed to read from the instrument! "）

 

        End If
        VI_txtOUT.Text = VI_txtOUT.Text & retCount

 

        If strRes = “” Then
             MsgBox（“nothing”）
         Else

             strRes = Mid（strRes， x + 3， y）
             FileOpen(1, Application.StartupPath + "\YouName.WMF", OpenMode.Output) '输出文档
             Print(1, strRes)
             FileClose(1)
         End If

 

        status = viSetAttribute(vi, VI_ATTR_TMO_VALUE, 2000) '设置超时为默认2秒
    End Sub