The Programmable Logic Solver (PLS) has been planned with no any cooperation and the Safety Integrity Level (SIL) is important and provable. The hardware contains of a kernel that uses diversity and redundancy of virtual hardware, while operating with the actual application of functional logic code. The I/O circuits affect the naturally fail-safe technology of SLS. The logic solver of PLS is placed in the module of Timer and Logic or ‘LT ’, and it performs all timer functions and functional logic, as defined in the Functional Logic Diagram application.
The modules of Logic & Timer, I/O modules, power supplies and the modules supporting can be arranged in a configurations number. In this method it is potential to further enlarge the Availability with fault-tolerance, or to select for a lower SIL for the safety of a less-critical process. ProSafe-DSP PLS is organized in autonomous completely functional units on system level, including the modules of I/O. These bricks of building are defined boxes, which can be interrelated to create a system with more capacity of I/O. There is no limitation of technical or practical to the maximum capability of PLS I/O handling by this approach. On the other hand, a system of Programmable Logic Solver (PLS) can be tailor created to the any sub-system size of the process, making distributed safety for the total place. The programmable PLS uses the same range of I/O modules and interfaces of communication, as the solid state SLS by the modular approach.
The essence of programmable logic solver
The robust safety accomplishment creates from its internal methodology of architecture and inherent self-test. Also the removal of all software system is a main breakthrough for a system of programmable safety. The design ensures the high safety performance integrity. The design in a dual or triple (TMR) error-tolerant architecture gives further improved availability. The logic processor of PLS is able of implementing all standard timer and logic functions, in a set program implementation cycle-time of a millisecond. The concept of Programmable Logic Solver (PLS) is according to the below fundamental foundations:
•No software system;
•No unnecessary the complexity circuit of hardware;
•All the circuits of safety-related and logic code are completely provable for the safety, not only in the normal operation, but in the particular, when one or more faults have arised;
•No compromises to safety.