Hanif Instrument Technology & Control
The proposed Control system is based on the safety-related and fault tolerant SIMATIC-S7 AS412FH automation system including regular and Fail Safe I/O modules as a combined control/ESD system. The redundant FH systems operate according to 1-out-of-2 principle and consist of two subsystems of identical design. These subsystems are electrically isolated from each other to achieve optimum EMC, and are synchronized with each other via fiber optic cables. A bump less switchover is made from the active subsystem to the standby one in the event of a fault. All FH systems are TUV-certified and comply with the safety requirement up to SIL 3 according to IEC 61508. The system is modular in construction with plug-in modules and is capable of future expansion by adding additional modules. Removal of one such module does not influence the overall system operation.