Title :
Emergency shutdown system
Author :
Sikora, Donald S. ; Jones, Ray L.
Author_Institution :
E.I. du Pont de Nemours & Co., Newark, DE, USA
Abstract :
A microprocessor-based emergency shutdown system using programmable logic controllers (PLCs) is described. This approach provides online diagnostic checking of input/output devices, verifies the operational response of shutdown logic, reduces the probability of a fail dangerous condition, and reduces false trips to rare events. It is concluded that, using this approach, the maintenance cycle will be shortened and the controllability of logic changes will be enhanced by having a self-documenting system in the PLC. It is believed that this is a step forward in the use of microprocessors for a safety interlock system. Cost savings will accrue due to reduced false or spurious shutdowns, reduced mean time to repair (MTTR) as a result of better diagnostic reporting, and reduced maintenance costs associated with periodic safety interlock verification
Keywords :
computerised monitoring; microcomputer applications; programmable controllers; safety systems; emergency shutdown system; logic; microprocessors; online diagnostic checking; programmable logic controllers; safety systems; self-documenting system; Control systems; Logic circuits; Logic devices; Logic testing; Microprocessors; Programmable control; Proposals; Relays; Safety; Solid state circuits;
Journal_Title :
Industry Applications, IEEE Transactions on
