Functional safety involves assessing and controlling all potential risks. Manufacturers of electronic components in particular, such as sensitive control systems and motor starters, have the issue of functional safety on their radar. However, machine manufacturers and system integrators also need to be familiar with the applicable standards in their respective fields in order to avoid potential liability claims on the part of the user.
The normative basis for functionally safe systems is the safety standard EN 61508. This internationally accepted seven-part standard is aimed at developers and system integrators alike as the basic standard for functional safety. It is therefore the 'guard rail' for all activities during the safety life cycle for systems that consist of electrical and/or electronic and/or programmable electronic elements and perform a safety function.

Relevant standards

The product standard EN 61800-5-2, which provides recommendations for the design, development, integration and validation of safety-related power drive systems, applies specifically to variable-speed drives for applications in industrial automation technology and mechanical engineering. It applies to systems with a high demand rate or continuous operation and provides a broad catalog of stop and monitoring functions.

Other applicable standards include:

- EN 62061 for safety-related control systems for machines;

- EN ISO 13849-1 and EN ISO 13849-2 for the integration of safety-related parts of machine control systems;

- EN 50126, EN 50128, EN 50129 for safety management and safety aspects in the railroad sector;

- EN 61511 for safety functions in the process industry.

In the automotive sector, ISO 26262 applies to electrical and/or electronic systems in road vehicles. For example, it applies to window regulators, light adjustment, brakes, steering or seat adjustment. The applicable range of safety standards must be taken into account right from the start of product development - whereby the term 'development' here does not stand for the realization of hardware or software, but already includes the concept and design phase and is always associated with a risk and hazard assessment of the overall system.

Protected from attacks

The EN 61508 standard forms the basic standard in the 'world of functional safety'. Various standards derived from it apply to the respective industry (e.g. automotive).

© System technology Leber

In addition to functional safety, security is playing an increasingly important role. If the developed, functionally safe systems are networked, they must be protected against external attacks - and thus made 'secure'. In the field of Industrial Control Systems (ICS), development must be carried out in accordance with the IEC 62443-4-1 standard.

The increasing networking of systems in the Internet of Things and in the autonomous vehicles of the future make a combination of safety and security aspects necessary and require the 'unification' of the seemingly contradictory demands on security with simultaneous end-to-end networking. This means that product development is becoming increasingly complex. The many, sometimes new requirements have an impact on the entire development process.

Development teams that can fall back on concepts that have already been tested and proven in practice have an advantage here - a 'construction kit' that includes not only the latest technology platforms, but also process models and solution concepts accumulated over the course of many projects. When implementing concrete, application-specific requirements, developers regularly encounter individual challenges when it comes to developing a 'consistently secure' system that meets the respective framework conditions. It is therefore advisable to fall back on existing 'modules' - processes, concepts and technologies that have either already achieved positive results in the past or have been developed and tested with a focus on a specific functionality in such a way that they can be efficiently integrated into individual products. On the one hand, this significantly reduces the risk of development failures and, on the other, prevents the costs of such a solution from being incalculable.

Examples of such modules are

- Technology components for communication technology (SoC, SoM);

- Integrated security functions and APIs;

- Drive control-specific design patterns for hardware and software;

- Proven verification and validation concepts for drive systems;

- Process models that are customized for the respective project.

These modules can be accessed as required. They are adapted or 'customized' depending on the application. As a result, drive control systems can be developed in accordance with both safety and security standards.