This Part of IEC 61131 specifies requirements and related tests for programmable controllers (PLC) and their associated peripherals (for example, programming and debugging tools (PADTs), human-machine interfaces (HMIs), etc.)which have as their intended use the control and command of machines and industrial processes.PLCs and their associated peripherals are intended to be used in an industrial environmentand may be provided as open or enclosed equipment. If a PLC or its associated peripheralsare Intended for use in other environments,then the specific requirements, standards andinstallation practices for those other environments must be additionally applied to the PLC and its associated peripherals.This standard also applies to any products performing the function of PLCs and/or theirassociated peripherals.Equipment covered in this standard is intended for use in overvoltage category II (IEC 60664-1)in low-voltage installations,where the rated mains supply voltage does not exceed a.c.1 000 V r.m.s.(50/60 Hz),or d.c.1 500 V.(If PLCs or their associated peripherals are appliedin overvoltage category III installations,then additional analysis will be required to determinethe suitability of the equipment for those applications.)This standard does not deal with the functional safety or other aspects of the overall automated system.PLCs,their application programme and their associated peripherals are considered as components of a control system.Since PLCs are component devices,safety considerations for the overall automated systemincluding installation and application are beyond the scope of this standard. However, PLC safety as related to electric shock and fire hazards, electrical interference immunity and errordetecting of the PLC-system operation (such as the use of parity checking, self-testingdiagnostics,etc.), are addressed.Refer to IEC 60364 or applicable national/local regulationsfor electrical installation and guidelines.The object of this standard is– to establish the definitions and identify the principal characteristics relevant to theselection and application of PLCs and their associated peripherals;– to specify the minimum requirements for functional, electrical, mechanical, environmental and construction characteristics, service conditions, safety, EMC, user programming and tests applicable to PLCs and the associated peripherals.This Part also specifiesa)service, storage and transportation requirements for PLCs and their associatedperipherals (Clause 4);b)functional requirements for PLCs and their associated peripherals (Clause 5);c)EMC requirements for PLCs and their associated peripherals (Clause 8);d)safety requirements for PLCs and their associated peripherals (Clause 11);e)information that the manufacturer is required to supply (Clauses 7, 10 and 13);f)test methods and procedures that are to be used for the verification of compliance of PLCs and their associated peripherals with the requirements (5.12, 8.5, 11.18 and Clause 13).The tests are type tests or production routine tests,and not tests related to the ways PLCsystems are applied.