IEC TC 57 has approved the New Work Item Proposal for IEC 61850-8-3 — a new Specific Communication Service Mapping that will define how ACSI services are carried over WebSocket and JSON. The vote closed in early March 2026 with only one dissenting national committee out of the full TC 57 membership. The standard will be developed.

What Was Just Approved

The approved proposal carries the document number 57/2866/NP and the provisional designation IEC 61850-8-3, Ed.1. Its formal title:

Communication networks and systems for power utility automation – Specific Communication Service Mapping (SCSM) – Mapping to Direct Message Specification (DMS), JSON Encoding Rules, and WebSockets

The NWIP was published for voting in December 2025 and circulated to all TC 57 national committees. When the deadline passed on March 6, 2026, the result was clear: approximately 95% voted in favour. As Karlheinz Schwarz, the designated editor, wrote in his NettedAutomation blog on the day the result was confirmed: "Today we are happy that the NWIP has been approved by IEC — only one country disagreed in the voting process."

What IEC 61850-8-3 Will Define

The new standard is a third SCSM — the third concrete protocol binding for the Abstract Communication Service Interface (ACSI) defined in IEC 61850-7-2. ACSI specifies what IEC 61850 systems do: GetDataValues, SetDataValues, reporting, logging, control, and other abstract services. The SCSM layers define how those services are carried on actual networks.

Today, two SCSMs are in use:

  • IEC 61850-8-1 maps ACSI onto MMS (Manufacturing Message Specification), carried over a full ISO stack. This is the foundation of substation automation as deployed worldwide for the last two decades. The encoding is BER (Basic Encoding Rules, ASN.1), the stack is heavy, and the operational context is the substation.
  • IEC 61850-8-2 maps ACSI onto XMPP, targeting ICT-layer integration. XML encoding, publish-subscribe model.

IEC 61850-8-3 adds a third path:

  • Transport: WebSocket (RFC 6455) — a persistent, full-duplex TCP channel. Unlike HTTP, WebSocket does not follow a request-response cycle for each exchange; once the connection is established, both client and server can transmit at any time.
  • Encoding: ASN.1 JER (JSON Encoding Rules, ISO/IEC 8825-8:2021). The message schemas are defined in ASN.1, but serialised as JSON — readable by standard web tooling.
  • Mapping model: direct. For every abstract ACSI service, IEC 61850-8-3 defines a concrete message schema for both the request and the response. There is no intermediate abstraction layer.
graph LR
    A[ACSI - IEC 61850-7-2] --> B[8-1: MMS / BER]
    A --> C[8-2: XMPP / XML]
    A --> D[8-3: WebSocket / JSON]
    B --> E[Substation Automation]
    C --> F[ICT Integration]
    D --> G[DSO Operations / Beyond Substation]

Why This Matters Beyond the Substation

The MMS stack in IEC 61850-8-1 is powerful and proven, but it was designed for the substation environment. Implementing it outside that context — in SCADA platforms, distribution management systems, energy management systems, or field devices operated by distribution-level utilities — has historically required protocol gateways, specialised middleware, or custom bridges.

IEC 61850-8-3 is designed for exactly those environments. WebSocket and JSON are native web technologies, broadly supported across platforms, languages, and operating systems. A DSO's operations centre, a DMS, a field edge device, or a cloud-based analytics platform can speak WebSocket/JSON without requiring the ISO protocol stack that MMS carries.

Schwarz framed the significance directly: "The result of this work will very likely change the usability of IEC 61850 outside substations."

For engineers working on IEC 61850 integration at the DSO level — connecting substations to control centres, building RTU-to-DMS interfaces, or designing grid-edge automation — this standard provides a path to native ACSI semantics without the MMS overhead.

The PoC That Started It

The NWIP did not emerge from a committee study group in isolation. It is the direct standardisation outcome of a Proof of Concept initiated and managed by Netbeheer Nederland, the body representing Dutch distribution system operators.

Schwarz, who participated in the PoC implementation, described it in December 2025 as demonstrating "the great benefit that can be harvested from the solution." The PoC established that WebSocket/JSON mapping for IEC 61850 ACSI services was technically viable, operationally useful, and worth bringing to the standards track.

That work is also the foundation of IEC 61850 Realtime Interface (RTI) v2.0, which documents how Dutch DSOs have deployed IEC 61850 at the operations level. RTI v2.0 represents the current practical implementation; IEC 61850-8-3 will be the international standard that formalises the approach.

What Comes Next

Approval of the NWIP is the beginning of the formal standards development process, not the end. The working group will now draft the standard, circulate Committee Drafts for comment, and move through the IEC balloting stages (CD, CDV, FDIS) before the final document is published. This process typically takes several years.

For now, the vote result establishes that TC 57 member bodies — the national committees responsible for IEC standards — see sufficient need and technical basis to invest in this work. The 95% approval rate is unusually strong.

Engineers and tool developers who want to follow the progress can do so through their national TC 57 committee. Copies of working documents at each stage are available through national body channels.

Sources