NEW!IEC 62138:2018 is available as IEC 62138:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 62138:2018 specifies requirements for the software of computer-based instrumentation and control (I&C) systems performing functions of safety category B or C as defined by IEC 61226. It complements IEC 60880 which provides requirements for the software of computer-based I&C systems performing functions of safety category A. It is consistent with, and complementary to, IEC 61513. Requirements that are not specific to software are deferred to IEC 61513. This new edition includes the following significant technical changes with respect to the previous edition: - align the standard with standards published or revised since the first edition, in particular IEC 61513, IEC 60880, IEC 62645 and IEC 62671; - merge two clauses in order to avoid repetitions of text; - introduce requirements on traceability in consistency with IEC 61513; - introduce new annexes.