Effects of Removing Block Diagram From LabVIEW VI

Issue Details

I want to remove the block diagram from my VI for security reasons. Are there any problems this may cause?

Solution

Most VI files have four sections - front panel, block diagram, code, and data. When you save a VI without diagrams, the block diagram portion is removed. The VIs will execute as they did with block diagrams but support of this VI under different LabVIEW versions and Operating Systems (OS) will be drastically reduced.

One of the great features of LabVIEW is that VIs, in general, are not OS or version specific. Every time you save a VI, the block diagram is compiled into machine language on the computer that is saving the VI. This machine language becomes the "code" section of the VI, mentioned above. Machine language is compiled code, and is specific to the particular version of LabVIEW, as well as the OS on which it was compiled.

Based on that information, once a VI is saved without diagrams:

• You can no longer make any editing changes or view the block diagram. 
• You cannot open or run the VI on any other version of LabVIEW, older or newer. If you try to do so, you will receive LabVIEW load error code 11: VI version cannot be converted to the current LabVIEW version because it has no block diagram.
• You cannot open or run the VI on any other OS.

Additional Information

There is no way to restore the block diagram once this operation has been completed. You should therefore always keep a backup of any VI saved without diagrams in case you ever want to port it to a different OS, a newer version of LabVIEW, or make any editing changes to it at a later time. Make sure that the backup of the VI you make includes the diagram. You can verify that the diagrams have been removed by determining if the following conditions are present:

• Hitting <Ctrl+E> does not make the block diagram appear. 
• The Show Block Diagram option is grayed out under the Window menu on the front panel and cannot be selected.
• When you navigate to File»VI Properties and select Protection from the resulting drop down menu, the Locked (no password) bubble is selected and every option is grayed out and cannot be manipulated 
• The Change to Edit Mode is grayed out under the Operate menu on the front panel and cannot be selected.

In LabVIEW 8.0 or later, if you want to remove the block diagrams you need to create a source distribution. For more detailed info please see the LabVIEW Help: Removing Block Diagrams from VIs. 
 

In LabVIEW 7.1 or previous, you could select File»Save with Options and save the VI without its block diagram using the dialog which pops up.