Glossary · Automation software engineering and architecture
Firmware
German: Firmware
In computing, firmware is software stored in non-volatile memory of a hardware device that provides its basic control, startup and operating functions, such as the operating software of a PLC, drive, sensor, network switch or communication module, and that is typically updated as a whole image.
- Software engineering
In one sentence
Firmware is software in a device's non-volatile memory that provides its basic control and operating functions and is updated as a whole.
Example
Before commissioning, the service engineer updates the PLC firmware to the version required by the engineering project and records it in the commissioning report.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
How it applies
- Engineering: Firmware versions determine which functions, protocols and bug fixes a device offers. Engineering projects are often tied to specific firmware versions, and combinations must be tested.
- Maintenance and security: Firmware updates fix defects and vulnerabilities but can change behavior. Plan them under change control, verify signatures, keep the previous version available and check compatibility with the application. Patch management processes cover firmware as well as software.
- Documentation: Record firmware versions of all devices in the machine documentation and commissioning report. Update instructions must include prerequisites, compatibility, procedure, verification and rollback. Release notes should state security fixes clearly.
Firmware vs. application software
Firmware comes from the device manufacturer and provides the platform; application software, such as a PLC program, is created by the machine builder and runs on that platform. Both have their own versions, and both must be documented for a machine to be reproducible.