Analyses of safety-related message transmission

The analyses were aimed at determination of failure effects in the transmission system, which allow identifying the transition process of the system from a safety state (it may not be necessarily a failure - a free state) to a dangerous state and permit to calculate probability of the dangerous state occurrence of the system as a failure effect to the operating system. Dangerous states of the safety Fieldbus system are mainly caused by systematic failures within a specification of the system, electromagnetic interferences (EMI) and random failures of the HW effects. The effects of electromagnetic interferences and random failures of HW can be described in the paper by the use of time table.