CIP Safety Embracing IEC 61784-3 Edition 4

Edition 4 of IEC 61784-3 (Functional safety fieldbus – General rules and profile definitions) was recently published in February of 2021.  It added several significant enhancements to address Timeliness errors, Authenticity errors and Masquerade errors to accompany the previously considered Data Integrity errors.  A new requirement was also included that requires proof of the effectiveness of the safety CRC polynomials used by a protocol, based on its residual error probability calculation.  The ODVA SIG for CIP Safety has been actively monitoring the development and normalization of the IEC 61784-3 standard.  To accommodate these new requirements raised in IEC 61784-3 Edition 4, several updates were made to the CIP Safety specification from Edition 2.20 to Edition 2.22.  Most notably, the Base format has been deprecated and the Max_Fault_Number has been adjusted. This white paper will first explain what major changes were introduced in IEC 61784-3 Edition 4 and why.  Second, the paper will discuss how the CIP Safety specification has adapted and evolved to maintain compliance. To call the attention of CIP Safety technology adopters, this paper will not only discuss the rationale behind these changes but that going forward how all products applying for an ODVA Declaration of Conformity will be expected to apply these protocol changes to their implementations, and when the required compliance became effective.

Paper and presentation from the 2022 ODVA Industry Conference  & 21st Annual Meeting