Distributed control systems are being used in the industry and in many Company facilities to implement alarm and shutdown systems. Integrating alarms and shutdowns into control systems can improve safety and reduce cost if done properly.
These systems can prioritize and sort incoming alarms to improve operator response to abnormal conditions that may possibly become dangerous.
Where regulatory agencies permit, distributed control system equipment can be used to implement shutdown system logic, because it satisfies the following requirements:
• Online testing of the sensors, shutdown valves, and logic.
• Segregation, documentation and verification of alarm and shutdown logic.
Dedicated hardware should be used both in the distributed control system and the sensing devices, and to implement protective logic in the most critical applications (e.g., personnel and environmental protection).