Glossary · PLC and control programming
Software
Also known as: Program code, Computer software
German: Software
In automation and computing, software is the set of programs, data and associated documentation that makes a computer, controller or device perform its functions, as distinct from the physical hardware.
- PLC programming
In one sentence
Software is the programs, data and documentation that make controllers and computers perform their functions.
Example
The software of a filling machine includes the PLC program, HMI project, drive parameters, recipe data and the firmware of the smart devices.
How it applies
- Engineering: In a machine, software is spread over many places: PLC programs, HMI projects, drive and robot programs, device firmware and parameters, edge applications. All of them determine behavior and must be managed together.
- Change management: Every software element needs an identifier and a version. The combination delivered with a machine forms its software Configuration baseline.
- Regulation: Software can be a safety component, a security risk or, in medical devices, a device itself. The Cyber Resilience Act and the Machinery Regulation address software in machinery and connected products; the applicable obligations depend on the product.
- Documentation: A software inventory (element, version, owner, location of the source) belongs in the technical documentation. Operating manuals should state how users find the installed software version, because service and updates depend on it.
Software vs. firmware
Firmware is software embedded in a device and closely tied to its hardware. The distinction matters for updates: firmware usually comes from the device vendor, application software from the machine builder or integrator.