Glossary · Automation fundamentals, platforms and components
Web server
Also known as: Integrated web server, Embedded web server
German: Webserver
In automation, a web server is software, often integrated in PLCs, drives, gateways or network devices, that provides information and functions through HTTP or HTTPS, such as device diagnostics, parameterization, user-defined web pages or REST APIs, accessible with a standard browser.
- Automation components
- OT security
In one sentence
A web server in automation devices provides diagnostics, settings or APIs via HTTP or HTTPS, reachable with a browser.
Example
The service technician opens the drive's integrated web server in a browser to read the fault history without installing the engineering software.
How it applies
- Engineering: Integrated web servers simplify diagnostics and allow simple visualizations without extra software. They are not a replacement for a proper HMI for machine operation.
- Security: Every web server enlarges the attack surface. Disable it if not needed, use HTTPS, change default credentials, restrict access by network and user, and keep firmware updated. These measures reflect the least-functionality and access-control principles of IEC 62443.
- Documentation: Device manuals must say whether the web server is enabled by default, which ports it uses, how to disable it and how user accounts and certificates are managed. Security guidance should be easy to find, not buried in an appendix.
Web server vs. cloud service
An integrated web server runs on the device and is reached over the local network. A cloud service runs elsewhere and receives data from the device, with different security and data protection considerations.