OCPP (Open Charge Point Protocol) is an open and widely used communication protocol specifically developed for electric vehicle (EV) charging stations or charge points. Its objective is to set efficient and secure connections between charging stations and central management systems. OCPP implies multiple functionalities such as secure transactions, diagnostics, power control, and data exchange.
Functions and Structure of OCPP
Message Flow | Description |
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Registration | |
CMS to Charging Station | Transfers a registration request to the charging station, enables identification and configuration information. |
Charging Station to CMS | Acknowledges the registration request, provides its identification and capabilities to the CMS. |
Status and Monitoring | |
CMS to Charging Station | Transfers a status request to the charging station to gather real-time information about its availability, power, and some other indicators. |
Charging Station to CMS | The charging station responds with the requested status information, including its availability, charging power, and any ongoing charging sessions. |
Charging Session Control | |
CMS to Charging Station | Starts a charging session via start command sent to the charging station, along with the necessary parameters. |
Charging Station to CMS | Acknowledges the start command and initiates the charging session, enabling status updates to the CMS. |
CMS to Charging Station | Sends commands to pause, restart, or terminate the charging session. |
Charging Station to CMS | Carries out the commands sent by the CMS, updating the charging session status. |
Transaction Handling | |
Charging Station to CMS | Sends transaction data, such as the start time, end time, energy consumption, and cost, to the CMS during and after the charging session. |
Firmware Updates | |
CMS to Charging Station | Sends firmware update requests to the charging station, with firmware files and instructions applied. |
Charging Station to CMS | Acknowledges the update request and performs the firmware update process, sending progress and completion notifications to the CMS. |
Influence on Device & Software Communication
Can all devices and networks labeled with the "OCPP tag" communicate with each other? The answer is yes, with one important consideration: the OCPP version. As long as the charging station management system and EV charging hardware both support the same OCPP version, it is possible to establish a connection between any OCPP hardware and software. For example, our go-e Chargers are designed to comply with the widely used OCPP 1.6 version. Therefore, they function flawlessly within a network where all other chargers also support this specific version. Here’s the list of existing versions:
OCPP 2.0.1
OCPP 1.6
OCPP 1.5
What Are the Key Obstacles of OCPP?
OCPP strongly relies on the connectivity between charge points and the backend application. Without it, they cannot operate, and providers cannot efficiently manage their devices. Cellular IoT is a popular connectivity option due to its global coverage and added security. In addition, there’s not enough remote access to charge points for reconfiguration, troubleshooting, and updates. This means on-site access and additional supply and logistic costs are applied.