Introduction ѕ IEC task compiler, ѕ Test and commissioning tools such as Tul32 and On- line Editor, ѕ PC-based PLC simulator: WinPLC32. Programming to IEC61131-3 provides the fol- lowing added benefits: ѕ Use of various programming languages, ѕ Programs structured by POUs (program organisation units) of type program, function and function block, ѕ Definition and declaration of variables of various data types as in high-level languages, ѕ Extensive libraries full of standard functions (e.g. for real numbers) and standard function blocks. For further information, please refer to the Quick Start Guide, E612GB, or the User's Guide, E614GB. E 327 GB 11 10.06.2003