Factory test and calibration

Developing effective engineering test and factory calibration software is a crucial part of any embedded product development project. For laser beam scanning products, the need is even greater due to the required mirror and laser calibration for safe, high performance operation.

Over the years our team has used both C#/.NET and LabVIEW for these applications, which need to operate in real-time and interface with test equipment, cameras, and manufacturing instrumentation. In this post I’ll share some best practices and lessons learned on development strategies for reliable factory test code.

Key Development Tools

The core languages we’ve used are:

• C#/.NET for its versatility, performance, and ease of development. Integrates well with instrumentation.
• LabVIEW for its real-time deterministic operation and compatibility with National Instruments hardware.

Software Architecture Considerations

Some key architecture aspects include:

• Standard host client DLL for device communication and control. Enables code reuse.
• Embedded scripting to execute device calibration routines. Allows optimization and customization.
• Modular design to separate key functionality like data analysis, test sequencing, and results logging. Improves maintainability.
• Simulation modes to facilitate debugging and hazard avoidance. Critical for laser systems.

Development & Experimentation Tools

For engineering development and prototyping, we rely on:

• Standalone C# apps for quick testing of algorithms and calibration routines.
• .NET scripting at the command line to experiment with parameters.
• Dedicated hardware-in-loop test benches for controlled experimentation.
• Logging and analytics to analyze results and characterize performance.

Factory test and calibration

For production test and calibration code we follow disciplined processes:

• Formal requirements documentation and design reviews.
• Traceability matrices linking code to test cases.
• Extensive simulation and hardware verification.
• Code reviews and static analysis to meet coding standards.
• Validation of statistical test limits and tolerances.
• Operator user interface designed for manufacturing environment.
• Automated test data logging and reporting for analytics.

In summary, developing reliable factory test and calibration code requires applying robust software engineering and validation principles tailored to the manufacturing environment. A modular code architecture, simulation capabilities, and disciplined processes are key. Both C# and LabVIEW have pros and cons, making a hybrid approach ideal.