Realzeitfähiger

Realzeitfähiger is the comparative form of the German adjective realzeitfähig, used to describe a system or component that has greater real-time capability than another. Realzeitfähig refers to the property of operating within predefined, deterministic time bounds so that inputs are processed and outputs produced with predictable latency and deadlines.

In engineering, realzeitfähige systems are designed to meet strict timing constraints under varying loads. Achieving this typically relies on real-time operating systems (RTOS), deterministic hardware, and software designs that minimize interrupt latency, use priority-based scheduling, and enable bounded worst-case execution times. The concept distinguishes between hard real-time, where missing a deadline constitutes a system failure; soft real-time, where occasional misses are acceptable; and firm real-time, where deadlines matter but occasional misses are allowed with degraded quality.

Real-time capability involves analyses and practices such as worst-case execution time (WCET) estimation, careful memory management, and avoidance of non-deterministic factors like variable garbage collection or unpredictable I/O delays. Realzeitfähige systems are common in fields such as embedded control, industrial automation, automotive and aerospace domains, robotics, and telecommunications.

Standards and related frameworks help specify and verify real-time behavior. POSIX real-time extensions define scheduling and timing interfaces for software. ARINC 653 and other partitioning standards address predictable services in safety-critical environments. Safety and reliability standards, such as IEC 61508 and ISO 26262, often impose timing requirements that influence real-time design.

In usage, the term is employed to compare components or systems regarding their ability to meet timing constraints: for example, a realzeitfähiger Rechner offers lower worst-case latency or more predictable response times than a less capable device.