IEC 62439-3:2016

Overview

IEC 62439-3:2016 - Industrial communication networks - High availability automation networks - Part 3: Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR) - defines two Ethernet-based redundancy protocols that deliver seamless recovery from single network or bridge/link failures by using parallel transmission of duplicated information. Edition 3.0 (2016) is a technical revision of the 2012 edition and adds technical corrections, extended specifications, and explicit consideration of IEC 61588 (PTP) clock synchronization using end-to-end delay measurement alongside peer-to-peer delay measurement in PRP.

Key Topics and Requirements

• PRP (Parallel Redundancy Protocol): topology options, doubly attached node structures (DANP), duplicate handling, PRP_Supervision frames, unicast/multicast addressing and service specification, and guidance for installation, configuration and repair.
• HSR (High-availability Seamless Redundancy): ring-based operation, DANH node and RedBox/QuadBox definitions, forwarding rules, HSR frame format, supervision, and deterministic medium access considerations.
• Clock synchronization: normative mapping and guidance for using PTP (IEC 61588 / IEEE C37.238) over redundant paths, including annexes on redundant clock attachment and PTP profiles for high-availability automation.
• Management and conformance: Protocol Implementation Conformance Statement (PICS), PRP/HSR MIB, supervision and redundancy management interfaces.
• Annexes: detailed normative annexes on PTP mapping, redundant clock models, and profiles for power-utility and automation applications; informative PTP tutorial.

Applications and Who Uses It

IEC 62439-3 is targeted at systems that require uninterrupted Ethernet communications and deterministic behavior in the face of single failures. Typical applications include:

• Power utility and substation automation
• Process control and manufacturing automation
• Railway signaling and transportation control
• Critical infrastructures requiring zero packet-loss on failure

Primary users:

• Network architects and automation engineers designing high-availability Ethernet networks
• System integrators and OEMs implementing PRP/HSR-capable devices
• Vendors creating switches, RedBoxes, and HSR/PRP endpoints
• Test labs and certification bodies verifying conformance (PICS, MIBs)

Related Standards

• IEC 61588 (Precision Time Protocol - PTP): referenced for clock synchronization over redundant paths.
• IEEE C37.238: relevant for PTP in power systems and referenced in mapping annexes.
• Other parts of the IEC 62439 series (for context on high-availability automation networks and implementation guidance).

Keywords: IEC 62439-3, PRP, HSR, high-availability automation networks, seamless redundancy, Parallel Redundancy Protocol, High-availability Seamless Redundancy, Ethernet redundancy, IEC 61588, PTP.