[Technology] The New Language-Version of EV Charger
The magic behind the OCPP 2.0.1
In my previous article, I explained what is an OCPP with a focus on OCPP 1.6
For those who didn’t have time to read it, OCPP is the language of most Electric vehicle chargers. For those who want to expand their knowledge about it feel free to check my article below:
What is OCPP protocol?
Every language in the world evolves. It acquires new vocabulary and gets rid of others. The language of EV chargers is not an exception. We moved from OCPP 1.6 to OCPP 2.0.1. This new version was created for three main reasons:
- Improve security
- Add new features
- Be more user friendly
Let us now dig a bit deeper into this new version of the OCPP.
- The OCPP 2.0.1 doesn’t support SOAP(XML) anymore; only Websocket.
- The OCPP 2.0.1 added the Plug and Charge feature. The car and the charging station will communicate with each other in order to handle the access and billing. There will be no need for a credit card, RFID card, or mobile app to start or stop a charging session.
- The OCPP 2.0.1 extended its smart charging functionality. With the dynamic load balancing the station can adjust its charging power in response to changes in the electricity load of the installation. Also, the communication between the charging station and the car is now bidirectional. When plugging in your car, the charging station can know exactly how much power your battery needs and tell you how much it will cost you if you want to charge 100%,80%, or 50%
- Data reduction is another benefit of the OCPP2.0.1
- In this new version, all the messages are encrypted to improve security. That’s why OCPP 2.0.1 doesn’t have profiles as its predecessor but blocks instead.
Talking about blocks, the OCPP 2.0.1 contains 16 different blocks which in turn contain several messages. If we compare it with the OCPP 1.6, the name of some messages has been changed to be more accurate and others have been added as well. Let’s have a look at the different blocks we have:
- Security — This Functional Block describes a security specification for the OCPP protocol.
- Provisioning — This Functional Block allows the Charge point operator to connect the station to its network and extract basic information. In this block, we can also reset the station, make it work offline, or migrate it to another network.
- Authorization — This Functional Block contains all the authorization messages in order to start a transaction. Besides RFID or local list, this new version brings into the table the authorization with pin code, credit/debit card, or simply plug and charge.
- Local Authorisation List Management — Same as the OCPP 1.6 this block allows you to have a list of RFID cards stored locally in the charging station.
- Transactions — This block allows you to have every information you need during the transaction. You can also start or stop the charging session.
- Remote Control — This block allows you to control the charging station remotely. You can start or stop the transaction but also unlock the connector.
- Availability — In this block, you’ll find those messages: Status Notification, Heartbeat, and others. If you’re curious about the meaning of those messages, please check my previous article.
- Reservation — Like the OCPP1.6 This Functional Block describes the reservation functionality of a Charging Station.
- Tariff and cost — This Functional Block is completely new and didn’t exist in the previous version of the OCPP. It Shows EV Driver-specific tariff information but also the total cost during and after charging.
- Metering — This Functional Block describes the functionality for sending meter values gathered by the charging station.
- Smart charging — This Functional Block contains several messages that allow the station to charge in a smart way. In OCPP1.6 we can set a charging profile to control the current/power in a specific period of time. The OCPP 2.0.1 has more than that. Thanks to Dynamic load balancing, you will never exceed the load of the whole installation.
- Firmware Management — This block allows you to update the firmware. The added value compared to the previous version is that you can do it in a very secure way.
- ISO 15 118 Certificate Management — All that I can say about this Functional Block is that it provides the installation and update of ISO 15118 certificates. ISO 15118 or the vehicle-to-grid communication interface is an international standard that defines bidirectional communication between the vehicle and the charging station or the electric grid in general.
- Diagnostics — As its name indicates, this block is useful to retrieve log information but also to set/get a monitoring report, to have alerts or periodic events, and also to get customer information.
- Display Message — From the CSMS (Charging Station Management System) you can now display a message on the screen of the charging station. All credit goes to this block.
- Data Transfer — like the previous version, this Block allows you to add custom commands to OCPP, enabling custom extension to OCPP. Generally, vendors put relevant information about the charging session in this OCPP message.