Functional Safety – SIL 3

There was a requirement to add safety instrumented system into existing application (lithium battery management). In coordination with project safety manager, we had to ensure that all hazardous situations are carefully analyzed and documented. There was implemented robust safe state in case of specific failure events. Project requirements envisioned SIL 3 level for E/E/PE control system. For controller safety itself, we deployed X-CUBE-STL library from SMT32, together with our implementation of recommended safety methods. We worked on developement of additional protection mechanisms (e.g. RAM buffer overwrite protection). Safety methods were activated on controller startup, periodically or triggered by events. There we used Flexible safety RTOS (Embedded Office) with specific configuration of memory space and process tasks. As part of project scope, we implemented continuous monitoring of analog and digital signals, used for taking process decisions. Controller was using communication peripherals CAN, I2C, SPI for data exchange with on board specific integrated devices.