IEC 61850-9-2-2020 PDF

Full title and description

St IEC 61850-9-2-2020 — Communication networks and systems for power utility automation — Part 9-2: Specific communication service mapping (SCSM) — Sampled values over ISO/IEC 8802-3 (consolidated edition incorporating Amendment 1:2020 to IEC 61850-9-2:2011). This publication defines the mapping and transmission of sampled measurement values (SV) for process‑level data (process bus) over Ethernet (ISO/IEC 8802-3), enabling standardized digital replacement of secondary copper connections for CTs and VTs in substations.

Abstract

IEC 61850-9-2 specifies the Specific Communication Service Mapping (SCSM) used to carry sampled values (SV) on Ethernet networks for substation automation. The document describes frame formats, timing and synchronization requirements, mapping rules for sampled analog quantities and associated metadata, and requirements that support interoperability between merging units (MUs), protection and control IEDs, and other process-bay devices. It is widely used as the basis for process‑bus implementations in modern digital substations.

General information

• Status: Published / active (consolidated edition: IEC 61850-9-2:2011 amended by AMD1:2020).
• Publication date: Amendment/publication date: 12 February 2020 (consolidated edition information shows Edition 2.0 with AMD1:2020 incorporated).
• Publisher: International Electrotechnical Commission (IEC), TC 57.
• ICS / categories: 33.200 (Power systems; substation automation communications).
• Edition / version: Edition 2.0 (IEC 61850-9-2:2011 + Amendment 1:2020 consolidated).
• Number of pages: 45 pages (consolidated document file size ~1.5 MB in IEC webstore listing).

Key bibliographic and technical metadata above are taken from the IEC publication entry for IEC 61850-9-2:2011/AMD1:2020.

Scope

The standard defines the Specific Communication Service Mapping (SCSM) for Sampled Values (SV) to be carried over ISO/IEC 8802-3 (Ethernet) and addresses the format and timing of SV streams, identification of signals and datasets, publisher/subscriber behavior, and synchronization requirements (including use of time sources such as PTP/GPS). Its scope focuses on process‑level communications between merging units, instrument transformers, and bay-level IEDs in substations to enable a digital process bus.

Key topics and requirements

• Definition of Sampled Values (SV) mapping onto Ethernet frames (SCSM) and required data structures (datasets, dataset element IDs).
• Frame format, sampling rate considerations and encoded representation of CT/VT derived samples.
• Timing, synchronization and determinism requirements for protection-grade data (PTP/IEEE 1588 and GPS/time sources implications).
• Interoperability requirements for merging units (MUs), publishers/subscribers and IEDs to support multivendor process bus deployments.
• Guidance on VLAN/priority usage, network design considerations to preserve latency and packet loss targets for SV traffic.

Typical use and users

Primary users are utility engineers, substation automation designers, protection and control engineers, IED and merging unit vendors, integrators, and test laboratories. The standard is used when implementing or specifying digital process-bus solutions that replace conventional hardwired secondary connections for protection and measurement, and during interoperability testing, plug‑fests, and vendor conformance activities.

Related standards

IEC 61850-9-2 is one part of the IEC 61850 family (which also includes parts addressing data models, MMS mappings, GOOSE, and system engineering). It is closely related to other IEC 61850 parts such as 8-1 (MMS and GOOSE mappings), 9-1 (Sampled values in earlier mappings), and technical reports on process-bus implementations; industry comparisons also reference IEC 61869-9 (instrument transformers) and IEEE/IEC timing standards (e.g., IEEE 1588/PTP) for synchronization. For interoperability and process-bus design guidance, CIGRE and IEEE literature are commonly referenced.

Keywords

IEC 61850; 9-2; Sampled Values (SV); Specific Communication Service Mapping (SCSM); process bus; merging unit (MU); substation automation; ISO/IEC 8802-3; synchronization; protection IED; PTP; digital substation.

FAQ

Q: What is this standard?

A: IEC 61850-9-2 (consolidated with Amendment 1:2020) specifies how sampled measurement values are formatted and transmitted over Ethernet (ISO/IEC 8802-3) for substation process‑level communications (the "process bus"). It is a SCSM (Specific Communication Service Mapping) within the IEC 61850 suite.

Q: What does it cover?

A: It covers the mapping of sampled analog/digital signals (from CTs/VTs and merging units) into Ethernet frames, sampling and dataset definitions, timing/synchronization requirements, publisher/subscriber behavior, and interoperability considerations needed for protection and measurement applications in substations.

Q: Who typically uses it?

A: Utilities, substation protection and control engineers, manufacturers of IEDs and merging units, system integrators, and test labs performing interoperability validation and process-bus deployments.

Q: Is it current or superseded?

A: The version referenced is the consolidated edition incorporating Amendment 1 published in 2020 (listed as IEC 61850-9-2:2011/AMD1:2020, Edition 2.0). As of the publication metadata the document is active and the IEC stability date shown for the publication is through 2026; users should check the IEC webstore or national bodies for any later amendments or revisions.

Q: Is it part of a series?

A: Yes — it is one part of the IEC 61850 series ("Communication networks and systems for power utility automation"), which includes multiple parts for modeling, mappings (MMS/GOOSE/SV), conformance, system engineering and testing. IEC 61850-9-2 specifically addresses the sampled values mapping for the process bus.

Q: What are the key keywords?

A: Sampled Values, SCSM, process bus, merging unit (MU), IEC 61850, ISO/IEC 8802-3, synchronization, protection IED, digital substation.