neopool-modbus 3.1.1

Async Python client for Sugar Valley NeoPool / VistaPool / Hidrolife Modbus pool controllers

neopool-modbus

Async Python client for NeoPool-based pool controllers connected via Modbus TCP. NeoPool is a control system originally developed by the Spanish company Sugar Valley (acquired by Hayward in 2016), sold under many brand names and product lines worldwide.

Supported device models (Sugar Valley / Hayward product lines): Hidrolife • Aquascenic • Oxilife • Bionet • Hidroniser • UVScenic • Station • Aquarite

Distributed by (vendors selling NeoPool-based hardware): Hayward • Brilix (Albixon) • Bayrol • Certikin • Poolstar • GrupAquadirect • Pentair • ProducPool • Pool Technologie • Kripsol

Note: VistaPool is the name of Hayward's mobile/web app for cloud-based pool management. This library communicates locally via Modbus TCP — it does not require or use the VistaPool app or any cloud service.

This library is the communication layer extracted from the Home Assistant neopool integration and is suitable for any async Python project — Home Assistant integrations, scripts, dashboards, or custom automation.

Installation

pip install neopool-modbus

Requires Python 3.13+ and pymodbus>=3.10.0 (installed transitively).

Quick start

import asyncio

from neopool_modbus import NeoPoolModbusClient


async def main() -> None:
    client = NeoPoolModbusClient(
        {"host": "192.168.1.42", "port": 502, "unit_id": 1}
    )
    try:
        data = await client.async_read_all()
        # Keys are the NeoPool register names defined by Sugar Valley
        # (mirrored from Tasmota's xsns_83_neopool.ino driver);
        # values are decoded into native Python types.
        print(f"pH:          {data['MBF_MEASURE_PH']}")           # e.g. 7.42
        print(f"Temperature: {data['MBF_MEASURE_TEMPERATURE']} °C")  # e.g. 27.3
        print(f"Hydrolysis:  {data['MBF_HIDRO_CURRENT']}")        # e.g. 6.5
    finally:
        await client.close()


asyncio.run(main())

The client is lazy — it opens the TCP connection on first use and reuses it across calls; close() releases the socket and resets retry/backoff state.

Reading individual registers

For one-off reads by address, async_read_register(address, count=1) picks the correct Modbus function code automatically: Read Input Registers (FC 0x04) for any address on the 0x01 page (MEASURE) and Read Holding Registers (FC 0x03) elsewhere.

from neopool_modbus import NeoPoolModbusClient

client = NeoPoolModbusClient({"host": "192.168.1.42"})

# Single register — pH level (raw u16, divide by 100 for pH 7.20)
ph_raw = (await client.async_read_register(0x0102))[0]

# Multi-register read (1-31; the firmware refuses larger requests).
# Combine the two halves of a 32-bit cell-runtime counter:
low, high = await client.async_read_register(0x0208, count=2)
partial_seconds = (high << 16) | low

The method validates the request before touching the wire and raises ValueError for out-of-range addresses, counts that exceed MAX_REGISTERS_PER_READ (31), or ranges that would either cross the input/holding namespace boundary or extend past the 16-bit address space.

Public API

from neopool_modbus import (
    NeoPoolModbusClient,
    NeoPoolError,
    NeoPoolConnectionError,
    NeoPoolModbusError,
    NeoPoolTimeoutError,
    async_probe_serial,
)
from neopool_modbus.registers import (
    CELL_BOOST_REGISTER,
    CLEAR_EEPROM_REGISTER,
    COMMAND_REGISTERS,
    COPY_TO_RTC_REGISTER,
    DEFAULT_MODBUS_FRAMER,
    DEVICE_TIME_REGISTER,
    EEPROM_SAVE_REGISTER,
    ESCAPE_REGISTER,
    EXEC_REGISTER,
    FILTRATION_CONF_REGISTER,
    FILTRATION_MODE_REGISTER,
    FILTRATION_SPEED_MASK,
    FILTRATION_SPEED_SHIFT,
    HEATING_SETPOINT_REGISTER,
    INPUT_REGISTER_RANGES,
    INTELLIGENT_SETPOINT_REGISTER,
    MANUAL_FILTRATION_REGISTER,
    MAX_REGISTERS_PER_READ,
    RESET_USER_COUNTERS_REGISTER,
    STOP_ALL_MODULES_REGISTER,
    TIMER_BLOCKS,
    is_input_register,
    is_valid_relay_gpio,
)
from neopool_modbus.capabilities import (
    CAPABILITY_KEYS,
    available_cell_boost_modes,
    available_filtration_modes,
    available_filtration_speeds,
    capability_snapshot,
    has_filtvalve,
    has_heating_relay,
    has_variable_speed_pump,
    is_chlorine_module_present,
    is_conductivity_module_present,
    is_heating_mode_enabled,
    is_hydrolysis_present,
    is_ionization_present,
    is_ph_module_present,
    is_redox_module_present,
    is_salinity_module_present,
    is_temperature_active,
    is_uv_lamp_present,
)
from neopool_modbus.decoders import (
    aggregate_filtration_remaining,
    build_timer_block,
    combine_u32,
    decode_cell_boost,
    decode_filtration_mode,
    decode_filtration_speed,
    decode_par_model_modules,
    derive_timer_stop,
    encode_cell_boost,
    encode_filtration_mode,
    encode_filtration_speed,
    get_machine_name,
    hhmm_to_seconds,
    is_hydrolysis_in_percent,
    parse_timer_block,
    seconds_to_hhmm,
    # ... see neopool_modbus.decoders for the full list
)
from neopool_modbus.status_mask import (
    decode_relay_state,
    decode_named_relay_states,
    decode_uv_lamp_state,
    decode_hidro_status_bits,
    decode_ion_status_bits,
    decode_ph_rx_cl_cd_status_bits,
)

Capabilities

neopool_modbus.capabilities exposes pure predicates over a register snapshot (whatever async_read_all last returned, or the persisted copy an integration keeps for offline / winter-mode operation):

from neopool_modbus.capabilities import (
    CAPABILITY_KEYS,
    capability_snapshot,
    is_hydrolysis_present,
    available_filtration_modes,
)

snapshot = capability_snapshot(data)        # only the keys predicates read
present = is_hydrolysis_present(data)       # bool
modes = available_filtration_modes(data)    # ("manual", "auto", ...)

CAPABILITY_KEYS is the canonical list of register names every predicate consults; persist capability_snapshot(data) (not the predicate outputs) and the same predicates work later when the device is offline.

High-level write methods

The client exposes named operations for the writes integrations typically need, so callers do not have to reach for raw register addresses:

Method	Effect
async_set_filtration_mode(name, apply=True)	manual / auto / heating / smart / intelligent / backwash
async_set_cell_boost(name, apply=True)	inactive / active / active_redox
async_set_filtration_speed(name, apply=False)	low / mid / high; RMW on MBF_PAR_FILTRATION_CONF (cache hot path, fresh-read cold path)
async_set_temp_setpoint(raw, apply=True)	writes the same scaled value to heating + intelligent registers in sync
async_clear_errors()	one-shot to MBF_ESCAPE
async_save_to_eeprom()	one-shot to MBF_SAVE_TO_EEPROM
async_reset_user_counters()	resets user counters and chains the EEPROM save (the reset is volatile)
async_sync_device_time(low, high)	writes the two halves of MBF_PAR_TIME and triggers MBF_ACTION_COPY_TO_RTC

Unknown mode/speed names raise ValueError before any I/O happens.

apply controls whether the write triggers an EEPROM save + EXEC after the value lands. The defaults match the operation's typical use: the filtration mode, cell boost and temperature setpoint persist by default; the filtration speed select stays volatile so frequent UI adjustments do not wear the controller's EEPROM.

All client methods translate underlying pymodbus exceptions into the NeoPoolError hierarchy at the library boundary, so callers never need to import pymodbus to catch errors:

Class	Raised when
NeoPoolConnectionError	TCP connect fails, returned False, or the client is in its post-failure backoff
NeoPoolTimeoutError	Connect, read, or write times out (asyncio.TimeoutError)
NeoPoolModbusError	A read returns a Modbus exception response (isError() true), or async_write_aux_relay / one of the timer write follow-ups returns isError()
NeoPoolError	Common base; catch this to handle any of the above

⚠️ NeoPoolModbusClient.async_write_register() is the exception to the table above: it returns None (rather than raising) on isError() so existing callers in the Home Assistant integration keep working. A future major release will tighten this to raise NeoPoolModbusError for consistency.

from neopool_modbus import NeoPoolError, NeoPoolModbusClient

client = NeoPoolModbusClient({"host": "192.168.1.42"})
try:
    data = await client.async_read_all()
except NeoPoolError as exc:
    # exc.__cause__ is the original pymodbus / asyncio exception, if any.
    print(f"NeoPool read failed: {exc}")

ValueError is still raised directly for programmer errors such as an out-of-range AUX relay index — those are not transport failures.

Features

• Async I/O on top of pymodbus.AsyncModbusTcpClient
• Batched register reads -- one round-trip per protocol page, with notification-bit-driven cache invalidation so unchanged pages skip the read
• Public read-by-address API (async_read_register) that automatically picks Read Input vs Read Holding based on the address
• High-level decoded views in async_read_all (filtration_mode, cell_boost_mode, installed_modules) and 32-bit register pairs (MBF_PAR_TIME, MBF_CELL_RUNTIME, ...) collapsed into single keys
• Named write operations for filtration mode / speed, cell boost, temp setpoint, time sync, error clear, EEPROM save, user-counter reset
• Pure capability predicates over a register snapshot, so an integration can drive UI gating both on live data and on a persisted offline copy
• Exponential connection retry with bounded backoff
• Write-and-verify cycle for configuration registers, with auto-clearing command registers (COMMAND_REGISTERS) excluded from verification
• Capability detection (hydrolysis, pH, Redox, chlorine, conductivity, ION)
• Strict type hints (py.typed), 100 % unit-test coverage

Logging

The library uses a single logger named neopool_modbus. Enable it like any other Python logger:

import logging
logging.getLogger("neopool_modbus").setLevel(logging.DEBUG)

Home Assistant users can flip the integration's "Enable debug logging" toggle in the UI; the integration's manifest.json lists neopool_modbus so the toggle covers the library too.

Based On

• Tasmota NeoPool driver — implements the NeoPool Modbus register protocol originally documented by Sugar Valley
• NeoPool Control System MODBUS Register description — a Markdown transcription of the official Modbus register documentation by Sugar Valley (see docs/modbus-registers.md)

Disclaimer

This library is provided "AS IS" and without any warranty or guarantee of any kind. The author takes no responsibility for any damage, loss, or malfunction resulting from the use or misuse of this code. Use at your own risk.

This project is not affiliated with or endorsed by Sugar Valley, Hayward, or any other pool equipment manufacturer or distributor.

"VistaPool" is a trademark of Hayward Industries, Inc. This library communicates locally via Modbus and does not use the VistaPool cloud service.

License

Apache 2.0 — see LICENSE.