Defines whether this I/O Block is written automatically when the Value property of its I/O Block Elements is modified. If this property is set to True, all changes are sent to the device associated to the I/O Driver. Otherwise, all modifications are ignored. I/O Block Elements do not accept values if this property is set to False, unless the AllowRead property is also set to False. The next script contains an example of using this property.

Sub Button1_Click()
  'Disables block writing
  Set obj = Application.GetObject("Driver1.block1")
  obj.AllowWrite = False
End Sub