Block Diagram

The Block Diagram is the part of a VI that contains the graphical source code known as G. Front Panel controls and indicators appear on the Block Diagram as control terminals. The control terminals for the Front Panel controls are the input where the Front Panel indicators are the output. Wires connect the terminals to other Nodes and each other to flow the data between them similar to a flow chart (see Dataflow). Operational order is dictated by Dataflow. Parts that are not connected are automatically parallelized by the compiler to take advantage of parallel processing that is available in modern multi-core computers.

Parts of a Block Diagram

• Top Level Diagram
• Control Terminals
• Nodes
  • Structures
    • Sub-Diagrams
  • Functions
  • SubVIs
• Constants
• Wires
• Decorations
  • Free Labels
    • Bookmarks

Best Practices

Code Organization

• Organize code to flow from Left-to-Right, Top-to-Bottom. Keep all input control terminals on the left and all output control terminals on the right.
• Do not place control terminals inside of Case Structures.

Code Size

If possible keep all code on a Block Diagram viewable on the screen without scrolling. Use SubVIs, Design patterns, etc. to organizes and enable code reuse. If necessary to scroll, only scroll in one direction, either Left and Right OR Up and Down.

Documentation

• When providing in-code documentation, document the Why's rather than the What's. If code is written well, what the code does should be easy to read. The documentation should help programmers viewing the code understand the original programmers reasoning and intent.
• Add documentation at the appropriate level. Documentation can be added to the VIs, Nodes, Wires, Subdiagrams, Constants and as Free Labels on the Block Diagram.

Design Patterns

Use commonly used Design patterns to standardize code organization among programmers.

See Also

• Front Panel