Glossary · Automation software engineering and architecture
Interface compatibility
German: Schnittstellenkompatibilität
In software and systems engineering, interface compatibility is the property that two components can interact correctly through an interface, because they agree on its operations, data structures, encodings, semantics, timing and version, so that one side can be changed or replaced without breaking the other.
- Software engineering
In one sentence
Interface compatibility means two components agree on an interface's operations, data, semantics and version, so they interact correctly.
Example
The new HMI version stays interface compatible with the existing PLC program because it reads the same data blocks and tolerates the older interface version.
How it applies
- Engineering: Compatibility can break in obvious ways, such as a removed field, or subtle ones, such as a changed unit, a new error code or different timing. Interface tests and contract tests detect many of these before release.
- Maintenance: For machines in the field, replacement parts and software updates must stay compatible with existing components. Compatibility matrices show which versions can be combined.
- Documentation: Release notes should state whether an interface change is compatible and in which direction. Keep compatibility matrices up to date and easy to find; service staff rely on them when replacing devices or updating software.
Interface compatibility vs. version compatibility
Version compatibility is the broader concept of how versions of components, data models or protocols work together. Interface compatibility focuses on one interface. Backward compatibility and Forward compatibility describe the direction: whether new components work with old partners, or old with new.