In all these projects our engineers were involved in programming/commissioning of both: process PLCs as well as safety related (HSE) systems.
Safety related systems were designed and programmed to fulfill SIL2 or SIL3 levels based on HAZOP:
- ESD (Emergency Shutdown) – emergency shutdown of the installation in case of dangerous situations
- F&G (Fire and Gas) – activation of alarming and firefighting systems in case of fire or gas detection
- PSD (Process Shutdown) – production shutdown in case of potentially dangerous situations (hazard may come from process itself or it might be signaled as an input from ESD/F&G systems).
Process PLCs are usually based on standard components of SIMATIC PCS7 system, while PLCs responsible for safety functions are built from components coming from Simatic S7 F/FH Systems family:
- redundant processors AS-400H (mainly CPU-417H/CPU-410)
- redundant fiber optic Ethernet networks
- redundant field networks Profibus (with ProfiSafe protocol)
- fail safe IO cards
- certified software tools (S7 F Systems with Failsafe Blocks Library).
In one system is realized both process control as well as fail-safe software that is rather seldom by other vendors. Safety logic is usually realized based on concept of Cause & Effect matrix.
Due to requirements of Oil&
