This technical report applies to the programming of programmable controller systems using the programming languages defined in IEC 61131-3. It also provides guidelines for the implementation of these languages in programmable controller systems and their programming support environments (PSEs).IEC 61131-4 should be consulted for other aspects of the application of programmable controller systems.NOTE Neither IEC 61131-3 nor this technical report explicitly addresses safety issues of programmable controller systems or their associated software. IEC 61508-1 and IEC 61508-7 should be consulted for such considerations.