01 Architecture

General

When working with clusters and SubVIs, pass only the data the SubVI needs. Do not let the SubVIs consume the entire cluster.

Do NOT use variant attributes for data storage unless their high performance is definitely needed.
- Attributes hide away any information about the datatypes at edit time

Wrap VIs in classes (.lvclass) or libraries (.lvlib) for name spacing and generally improved encapsulation / cohesion / coupling
- See Organising Code for details

If a technology supports multiple threads (more than one instance in memory at the same time), all the VIs of the corresponding driver usually need to be set to reentrant execution.

Do NOT use invert options on boolean functions and operators
- use a separate not operator instead

For constants that are reused throughout the project, create a subVI that only contains a single constant on the block diagram and one indicator returning the constant value
- append –constant to the VI name
- See 02 Layout & Design for VI icon design

When using CD Structures, put them into the project tree:
- as far up as possible (ie. direct at the project root level, as opposed to the targets)
- as far down as necessary (eg to distinguish different FPGA targets)

For each CD Symbol in the project, add a log entry or similar to your project so you can identify at runtime which values were defined for the symbols
- Put these into a subVI directly after starting the application
- When using HSE libs, put this subVI directly after initialising the HSE-Logger

Wrap each query in a separate SubVI
- this allows for easy reuse
- add documentation to describe the returned values
- optional: convert the returned 2d-array of strings into a 1d-array of typedef'ed cluster

Simultaneous Creation: When creating access to a configuration file, the file and its related content must be created at the same time.
Focused SubVI Design: A configuration access SubVI should only contain related information. This minimizes dependencies and simplifies maintenance and testing.
Early Testing: Perform testing early to identify and resolve potential issues promptly, avoiding prolonged troubleshooting later.
Default Config Creation: Implement a VI that creates a configuration file in the correct format, even if the application does not have a “save config” requirement, ensuring consistency and avoiding potential issues.

Units in Square Brackets: Append units in square brackets [ ] to the variable name.
- Examples: distance[km], time[s], temperature[°C].
Standard Units: Use SI units where possible. Non-SI units must be consistent and documented.
- Examples: force[N], speed[km/h].
No Unit: Use [-] if the variable is unitless.
- Example: scalingFactor[-].
- Special Note: If the variable represents a fraction (e.g., a ratio), where the value ranges from 0 to 1 without explicit scaling use [-]. If a variable represents a percantage use [%] instead.
No Redundancy: Do not repeat units in both the variable name and value.
- Correct: distance[km] = 50
- Incorrect: distance_km = 50 km.

The Array to Cluster node has the number of elements hard-coded
As an array is dynamic, we need to check the size during runtime
To convert the generic cluster to a typedef-ed one, use the Coerce To Type function