OCPP

Python package implementing the JSON version of the Open Charge Point Protocol (OCPP). Currently OCPP 1.6 (errata v4), OCPP 2.0.1 (Edition 2 FINAL, 2022-12-15) are supported.

You can find the documentation on rtd.

The purpose of this library is to provide the building blocks to construct a charging station/charge point and/or charging station management system (CSMS)/central system. The library does not provide a completed solution, as any implementation is specific for its intended use. The documents in this library should be inspected, as these documents provided guidance on how best to build a complete solution.

Note: "OCPP 2.0.1 contains fixes for all the known issues, to date, not only the fixes to the messages. This version replaces OCPP 2.0. OCA advises implementers of OCPP to no longer implement OCPP 2.0 and only use version 2.0.1 going forward."

Installation

You can either the project install from Pypi:

$ pip install ocpp

Or clone the project and install it manually using:

$ pip install .

Quick start

Below you can find examples on how to create a simple OCPP 1.6 or 2.0.1 Central System/CSMS as well as the respective OCPP 1.6 or 2.0.1 Charging Station/Charge Point.

$ pip install websockets

Charging Station Management System (CSMS) / Central System

The code snippet below creates a simple OCPP 2.0.1 CSMS which is able to handle BootNotification calls. You can find a detailed explanation of the code in the Central System documentation.

import asyncio
import logging
import websockets
from datetime import datetime

from ocpp.routing import on
from ocpp.v201 import ChargePoint as cp
from ocpp.v201 import call_result
from ocpp.v201.enums import RegistrationStatusType

logging.basicConfig(level=logging.INFO)


class ChargePoint(cp):
    @on('BootNotification')
    async def on_boot_notification(self, charging_station, reason, **kwargs):
        return call_result.BootNotificationPayload(
            current_time=datetime.utcnow().isoformat(),
            interval=10,
            status=RegistrationStatusType.accepted
        )


async def on_connect(websocket, path):
    """ For every new charge point that connects, create a ChargePoint
    instance and start listening for messages.
    """
    try:
        requested_protocols = websocket.request_headers[
            'Sec-WebSocket-Protocol']
    except KeyError:
        logging.info("Client hasn't requested any Subprotocol. "
                 "Closing Connection")
        return await websocket.close()

    if websocket.subprotocol:
        logging.info("Protocols Matched: %s", websocket.subprotocol)
    else:
        # In the websockets lib if no subprotocols are supported by the
        # client and the server, it proceeds without a subprotocol,
        # so we have to manually close the connection.
        logging.warning('Protocols Mismatched | Expected Subprotocols: %s,'
                        ' but client supports  %s | Closing connection',
                        websocket.available_subprotocols,
                        requested_protocols)
        return await websocket.close()

    charge_point_id = path.strip('/')
    cp = ChargePoint(charge_point_id, websocket)

    await cp.start()


async def main():
    server = await websockets.serve(
        on_connect,
        '0.0.0.0',
        9000,
        subprotocols=['ocpp2.0.1']
    )
    logging.info("WebSocket Server Started")
    await server.wait_closed()

if __name__ == '__main__':
    asyncio.run(main())

Charging Station / Charge point

import asyncio

from ocpp.v201.enums import RegistrationStatusType
import logging
import websockets

from ocpp.v201 import call
from ocpp.v201 import ChargePoint as cp

logging.basicConfig(level=logging.INFO)


class ChargePoint(cp):

    async def send_boot_notification(self):
        request = call.BootNotificationPayload(
            charging_station={
                'model': 'Wallbox XYZ',
                'vendor_name': 'anewone'
            },
            reason="PowerUp"
        )
        response = await self.call(request)

        if response.status == RegistrationStatusType.accepted:
            print("Connected to central system.")


async def main():
    async with websockets.connect(
            'ws://localhost:9000/CP_1',
            subprotocols=['ocpp2.0.1']
    ) as ws:
        cp = ChargePoint('CP_1', ws)

        await asyncio.gather(cp.start(), cp.send_boot_notification())


if __name__ == '__main__':
    asyncio.run(main())

Debugging

Python's default log level is logging.WARNING. As result most of the logs generated by this package are discarded. To see the log output of this package lower the log level to logging.DEBUG.

import logging
logging.basicConfig(level=logging.DEBUG)

However, this approach defines the log level for the complete logging system. In other words: the log level of all dependencies is set to logging.DEBUG.

To lower the logs for this package only use the following code:

import logging
logging.getLogger('ocpp').setLevel(level=logging.DEBUG)
logging.getLogger('ocpp').addHandler(logging.StreamHandler())

License

Except from the documents in docs/v16 and docs/v201 everything is licensed under MIT. © The Mobility House

The documents in docs/v16 and docs/v201 are licensed under Creative Commons Attribution-NoDerivatives 4.0 International Public License.