AS IEC 61131.6 pdf download – Programmable controllers Part 6: Functional safety This Part of the IEC 61 1 31 series specifies requirements for programmable controllers (PLCs) and their associated peripherals, as defined in Part 1 , which are intended to be used as the logic subsystem of an electrical/electronic/programmable electronic (E/E/PE) safety-related system. A programmable controller and its associated...