DIN SPEC 70121 2014-12 PDF

Full title and description

DIN SPEC 70121:2014-12 — Electromobility: Digital communication between a d.c. EV charging station and an electric vehicle for control of d.c. charging in the Combined Charging System (text in English). This pre-standard defines the signalling and higher-layer message exchange (PLC-based) used for DC fast charging under the CCS interface.

Abstract

DIN SPEC 70121:2014-12 specifies the digital communication protocol used between an EV and DC EV supply equipment (EVSE) for control of d.c. charging in the Combined Charging System (CCS). The document is based on requirements from ISO/IEC 15118-2 and focuses on the protocol behaviour, message flows and PLC transport details needed to establish and manage DC charging sessions.

General information

• Status: Withdrawn / Superseded (document replaced by DIN/TS 70121:2024-11).
• Publication date: 2014-12 (December 2014).
• Publisher: Deutsches Institut für Normung (DIN).
• ICS / categories: 29.160.40, 43.120.
• Edition / version: DIN SPEC 70121:2014-12 (pre‑standard).
• Number of pages: 212.

Scope

Defines the digital communication between a d.c. EV charging station (EVSE) and an electric vehicle (EV) for controlling DC charging within the Combined Charging System. The focus is on PLC transport (HomePlug Green PHY where applicable), the application-layer message sequences for charge negotiation and session control, and the required behaviours for EV and EVSE to interoperate for DC fast charging. The specification is explicitly based on and references ISO/IEC 15118-2 requirements.

Key topics and requirements

• Protocol architecture and message sequences for DC charging (ChargeParameterDiscovery, session setup and termination).
• Use of power-line carrier communications (HomePlug Green PHY / PLC) and SLAC (link-layer discovery/association) behaviour.
• Definition of EVCC / SECC roles and expected responses from EV and EVSE during a charge session.
• Requirements for charge negotiation, available power reporting and limits when DIN SPEC 70121 protocol is selected.
• Interoperability notes and normative references to ISO/IEC 15118 family and IEC charging standards (behavioural alignment with the wider EV charging standards ecosystem).

Typical use and users

Primary users are vehicle manufacturers, EV component suppliers (EVCC), EVSE manufacturers and network/charge point operators seeking to implement interoperable DC charging communications for CCS. The document served as an industry transitional specification to enable PLC-based digital signalling for DC fast charging prior to broader adoption of later ISO 15118 versions and related standards.

Related standards

Closely related to and referencing ISO/IEC 15118-2 (vehicle-to-grid communication for conductive charging), IEC 61851 series (conductive charging), and later ISO 15118 extensions. DIN SPEC 70121 was an industry bridge based on early ISO 15118 drafts; it has since been superseded by DIN/TS 70121:2024-11, which updates and replaces the 2014 text. For differences in security and Plug & Charge capabilities versus later ISO 15118 editions, see contemporary comparisons between DIN SPEC 70121 and ISO 15118.

Keywords

DIN SPEC 70121, DC charging, CCS, EVSE, EVCC, HomePlug Green PHY, PLC, SLAC, ChargeParameterDiscovery, ISO 15118-2, Plug and Charge (legacy / partial), V2G (context).

FAQ

Q: What is this standard?

A: DIN SPEC 70121:2014-12 is a DIN pre-standard that specifies the digital communication protocol used between an EV and a DC EVSE for control of DC charging under the Combined Charging System (CCS).

Q: What does it cover?

A: It covers PLC-based transport and higher‑layer message flows for DC fast charging (including SLAC/PLC behaviours and charge negotiation messages). It is focused on enabling interoperable digital signalling for DC charging sessions and references ISO/IEC 15118-2 requirements.

Q: Who typically uses it?

A: Vehicle OEMs, EVSE manufacturers, communication-controller vendors (EVCC/SECC suppliers), and charge‑point operators used DIN SPEC 70121 as a practical implementation reference for DC charging communication.

Q: Is it current or superseded?

A: DIN SPEC 70121:2014-12 has been superseded and replaced by DIN/TS 70121:2024-11 (published November 1, 2024); implementers should consult the newer DIN/TS text for up-to-date requirements.

Q: Is it part of a series?

A: Yes — DIN SPEC 70121 sits in the ecosystem of EV charging communication documents that reference and align with the ISO/IEC 15118 family and IEC charging standards. It was created as an early, DIN-level specification to harmonize DC charging signalling in the CCS context.

Q: What are the key keywords?

A: DC charging, CCS, EVSE, EVCC, HomePlug Green PHY, PLC, SLAC, ISO 15118-2, charge negotiation, plug-and-charge (limited capabilities in this spec).