How to read block data continuously?

hi:

     I found that I can only read the maximum of 4096kb using “viread”.So I think the max block size of instrument can only be 4096kb.

              status = viReadToFile(vi, "D:\YouName.WMF", 72676, retCount) 

              the result is  retCount = 4096

  I  continuous  use "viread ",but only first work.

   How to read block data continuously?

status = viVPrintf(vi, "YST:COMM:GPIB:RTER EOI" + vbCrLf, 0) 
status = viVPrintf(vi, ":HCOPEV:LANG WMF" + vbCrLf, 0) 
status = viSetAttribute(vi, VI_ATTR_TMO_VALUE, 20000)
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) 
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 = 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", 4096, retCount) 
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)
status = viReadToFile(vi, "D:\YouName.WMF", 4096, retCount)