Programmable logic controllers (PLCs) and similar network-compatible components for industrial use increasingly feature services also found in server systems. Given the increasing interconnectedness of these components, these general services as well as specific functions of automation technology require a sufficient level of security. The present document provides product suppliers with an overview of the essential best practices for components of this type. In addition, the BSI offers a guide for manufacturers of industrial components which is intended to support the setup of product tests and security analyses. Mechanical engineers and integrators can use this document in the context of their product development to address security-related requirements.