OCPP 2.0.1 is the version the Open Charge Alliance published in 2020 to replace 1.6. The intermediate 2.0 release had issues that were fixed and re-released as 2.0.1, which is why the field always talks about "2.0.1" rather than "2.0". This article explains what 2.0.1 changes and what it means for a charge point operator.

OCPP 2.0.1 in brief

Like 1.6J, OCPP 2.0.1 carries JSON messages over WebSocket. The message set and concepts, however, were reorganised from the ground up. The central system is now officially called the CSMS (Charging Station Management System), and the device is called the Charging Station. A station contains one or more EVSEs, and each EVSE has one or more connectors. This three-level structure models multi-outlet chargers far more clearly than 1.6 did.

Main improvements over 1.6J

Single-message transaction handling: TransactionEvent

In 1.6, StartTransaction, StopTransaction and MeterValues were separate messages. In 2.0.1 they are replaced by TransactionEvent. A charging transaction is managed through one message type with Started, Updated and Ended events. The transaction ID is now generated by the charger. This structure reduces data loss during connection drops and keeps transaction history more consistent.

Device Model

Instead of the flat "key=value" configuration list of 1.6, 2.0.1 uses a hierarchical device model made of components and variables. Configuration is handled with SetVariables and GetVariables. The charger can describe everything it supports to the CSMS with NotifyReport. This makes it easier to manage different brands with the same logic.

Built-in security

In 2.0.1, security is an integral part of the protocol. It defines three security profiles (Basic Auth, TLS + Basic Auth, and TLS with client certificates), certificate management messages and security event notifications.

Advanced smart charging

Charging profiles are kept and extended. With ISO 15118, the vehicle's charging needs can be used for smarter planning. Limits from an external energy management system can also be included in the model.

Better user experience

Features such as messages shown on the charger screen (SetDisplayMessage), multi-language support and showing tariff and cost information to the driver have been added.

Is 2.0.1 compatible with 1.6?

No. 2.0.1 is not backward compatible with 1.6J. A charger speaks either 1.6J or 2.0.1 (some support both but use one at a time). The WebSocket subprotocol name is also different: ocpp2.0.1 instead of ocpp1.6. This means your management software needs to support both versions.

When should you choose 2.0.1?

  • If you are building a new public charging network with long-term security requirements,
  • If you are aiming for Plug & Charge (ISO 15118),
  • If you need to manage multi-EVSE DC chargers in detail,
  • If you want to show prices and messages on the charger screen.

On the other hand, if most of your installed base runs 1.6J, choosing a platform that manages both in the same dashboard makes the transition painless. To see the versions side by side, read our OCPP 1.6J, 2.0.1 and 2.1 comparison.

What to watch out for when migrating

Moving from 1.6J to 2.0.1 is not just a software setting. The charger firmware must support 2.0.1, the OCPP URL and security profile must be reconfigured, and client certificates may need to be installed. On the reporting side, take into account that transaction IDs are now generated by the charger and that a single transaction is completed through several TransactionEvent messages. Starting with a pilot of a few chargers is the safest way to confirm that billing and reports work as expected. Running 1.6J and 2.0.1 chargers side by side at the same location during the pilot and comparing session data helps you catch differences early.

Conclusion

OCPP 2.0.1 is a modern version that simplifies transaction handling, describes chargers with a standard model and puts security at the heart of the protocol. It is a strong first choice for new investments, but 1.6J chargers will remain in the field for many years. Üreticy's OCPP software manages 1.6J, 2.0.1 and 2.1 chargers together in one dashboard.