Electronic Hardware for Safety Critical Applications

Electronic Hardware

Electronic Hardware intended for safety-critical applications must be designed for such applications. Just as Operating Systems designed for desktop computing applications are not appropriate for safety critical tasks, hardware designed for desktop or general computing is often not appropriate for safety critical systems.

Electronic hardware for safety critical applications can be based on either generic 'building blocks' such as Programmable Logic Controllers (PLCs) or on custom electronic hardware. Advanced Diving Systems (ADS) has chosen to develop custom hardware for our products. While this approach involves substantial upfront design effort, it significantly improves our ability to supply affordable and compact products while meeting high standards for safety and reliability.

Designing for Reliability

Electronic hardware intended for safety-critical applications must be designed for reliability across a range of environmental conditions. When developing safety-critical hardware, it is standard practice to use formal techniques for evaluating the design. These analysis techniques involving a systematic and quantitate analysis of hardware failure rates and modes to determine whether target reliability levels have been achieved.

Designed for Safety

Specific functionality must often be designed into electronic hardware for safety-critical applications in order to meet safety targets. An example of this is the use of a so-called “windowed watchdog timer” which is an independent electronic component that monitors the primary system clock and verifies that it is operating at the correct speed. This feature, one of many examples, is important because correctly accounting for time is critical to safety in diving applications involving decompression management.