pyiont

Asynchronous Python client for IONT EV chargers over Modbus TCP.

The library is built on modbus-connection: it takes a ModbusUnit, maps the charger's register blocks to typed attributes, and exposes the commands the charger accepts. It has no Home Assistant dependency and is the device layer of the Home Assistant iont integration.

Install

pip install "pyiont[tmodbus]"    # tmodbus backend
pip install "pyiont[pymodbus]"   # pymodbus backend

Prerequisites

Modbus TCP has to be enabled on the charger, in its administration interface under Protocols. Writing (authorization, power limit) is a separate switch there and is off by default. The charger listens on port 502.

Example

import asyncio

from modbus_connection import ModbusTcpParams
from modbus_connection.tmodbus import ModbusConnection

from pyiont import IontCharger


async def main() -> None:
    connection = ModbusConnection(ModbusTcpParams(host="192.168.1.60", port=502))
    try:
        charger = await IontCharger.async_probe(connection.for_unit(1))
        report = await charger.async_update()

        print("Status:", charger.device.status.name.lower())
        print("Available power:", charger.device.available_power, "W")
        for number, connector in enumerate(charger.connectors, 1):
            print(
                f"Connector {number}:",
                connector.charging_state.name.lower(),
                connector.power,
                "W",
                connector.session_energy,
                "Wh",
            )
        print("Failed sub-systems:", report.failed)

        await charger.async_authorize(1)  # start charging on connector 1
        await charger.async_set_external_power_limit(7_400)  # cap at 7.4 kW
    finally:
        await connection.close()


asyncio.run(main())

What it reads

• Device: breaker limits, phase count, free-charging mode, user power ceiling, available power, charging strategy, status, uptime, connector count.
• Settings: the external power limit (writable).
• Connector (one block per connector): connection and vehicle state, charging state, authorization and its source, power, per-phase voltage, current and frequency, session, last-session and lifetime energy, battery state of charge (DC), inner and ambient temperature.

async_update() reads each sub-system on its own and returns an UpdateReport naming what refreshed and what failed, so one silent connector does not blank the rest. A link that answers nothing raises IontConnectionError.

Commands

• async_authorize(number, boost=False) / async_deauthorize(number): start or stop charging on a connector by its 1-based number. boost=True charges at full available current even under the eco strategy.
• async_authorize_by_id(connector_id) / async_deauthorize_by_id(connector_id): the same, addressing the connector by its OCPP connector ID.
• async_set_external_power_limit(watts) / async_clear_external_power_limit(): cap the charging power from outside, for example from a home energy manager.

A command that the charger does not process in time, or reports a result other than success for, raises IontCommandError.

Develop

uv sync --extra tmodbus
uv run pytest
uv run mypy
uv run ruff check

License

MIT