Data flow

Dataflow programming is a programming paradigm where the execution of functions is determined by their data dependencies. This is fundamentally different from traditional programming paradigms that execute functions in sequence as they appear in the source code.

LabVIEW dataflow model

LabVIEW uses the graphical programming language G Dataflow, which utilizes wires to represent data dependencies between functions (nodes in LabVIEW terminology).

A node without input wires can execute immediately, while a node with input wires must wait until the previous node has finished execution.

A node without input wires executes immediately.

A node with input wires waits for the previous node to finish execution.

It is also possible to execute multiple nodes in parallel, as long as they have no data dependencies between each other. However, the total number of nodes that can execute in parallel is limited by the execution system.

Nodes without data dependencies execute in parallel. (Note: Execution highlighting forces the code to run in a single thread which is why they appear to execute sequentially).

Visualizing dataflow in LabVIEW

The debugging option "Execution Highlighting" will visualize the flow of data while executing a VI in LabVIEW.

This, however, forces the code to run in a single thread, which causes nodes to execute sequentially.

See also

• G Dataflow
• Debugging
• LabVIEW Execution System

External links

• Wikipedia:Dataflow programming (Wikipedia)
• Dataflow Programming Basics (National Instruments)