Maximum Size for LabVIEW Front Panel and Block Diagram

Issue Details

• I'm working on a VI that's quite large, and it takes time to perform basic actions like moving things in the diagram. This VI may have been corrupted recently, as shown in Figure 1. 
• I have a very large block diagram that is starting to act buggy. Why is this happening? How do I fix this?
• I am not be able to open the block diagram, or it might appear that my VI is running continuously without actually running.
• Is there a maximum size limit for the front panel or block diagram in LabVIEW? What happens if I exceed this size?

Solution

Both the front panel and block diagram have a maximum width and height of 2^16 pixels, and can span from -32768 to 32767 pixels around the origin. If you begin to approach or exceed this limit, you will encounter unexpected behavior.

To view the current size of your diagram, go to Tools » Profile » VI Metrics and select Diagram. VI Metrics is available in the LabVIEW Professional Development System.

Exceeding the maximum front panel size will cause the front panel to become corrupt, and some of the front panel features (scroll bar, etc.) will function incorrectly. This behavior is also present on the block diagram in similar situations. 

To avoid corruption that may come with the block diagram becoming too large, try these options:

• Use subVIs in your code to increase your code's modularity. For more information on code modularity using subVIs, see LabVIEW SubVIs Explained.
• Architect your code with a state machine structure.

Depending on how corrupted is your block diagram after exceeding the limits, there may be some sections of the code that can be recovered to copy and paste them in a new VI. You can go to View » Navigation Window to get a whole picture of the block diagram. Clicking any section of the code inside the Navigation Window will take you to that section of the code in the block diagram.

Additional Information

To demonstrate erratic behavior due to an oversize front panel, you can create a VI that has one numeric control close to the origin, and one numeric control close to the maximum size limits of the front panel (~32000, ~32000). After placing these controls, if you try to move the second numeric control any lower or more right, you may see that the numeric control and front panel are displayed incorrectly.