CLAD Software Development Best Practices 4

Question 1

What is the recommended way to document a subVI's purpose for other developers in LabVIEW?

Accepted Answer

Fill in the VI Properties > Documentation section with a description

Answer

The VI Properties Documentation field is the standard location for VI-level descriptions visible in Context Help and the VI Analyzer.

Question 2

Which LabVIEW coding practice helps prevent 'spaghetti code' on the block diagram?

Accepted Answer

Breaking complex logic into well-named subVIs and keeping diagrams small

Answer

Encapsulating logical units into named subVIs keeps each block diagram small and readable, similar to functions in text-based languages.

Question 3

In LabVIEW, what is a 'functional global variable' (FGV) and what problem does it solve?

Accepted Answer

A single-loop subVI that uses uninitialized shift registers to store state in a thread-safe way

Answer

An FGV uses an uninitialized shift register inside a subVI to hold state, providing controlled, single-access-point data storage that avoids race conditions.

Question 4

When reviewing LabVIEW code for performance, which issue most commonly causes unnecessarily high CPU usage in a loop?

Accepted Answer

Missing a wait function, causing the loop to spin as fast as possible

Answer

Without a Wait or Wait Until Next Ms Multiple function, a loop consumes 100% of a CPU core by executing as fast as possible.

Question 5

What is the advantage of using LabVIEW's 'built application' (.exe) for deployment rather than shipping source VIs?

Accepted Answer

It protects intellectual property and does not require LabVIEW Development environment on the target machine

Answer

A built executable hides source code and only requires the free LabVIEW Runtime Engine on the target machine, not the full development environment.

CLAD Practice Test

CLAD Practice Test

CLAD Software Development Best Practices 4