Implement pymodbus register map for Sigenergy SigenStor battery system

Create pymodbus TCP client in sigentrol that reads all relevant battery, inverter, and PV registers. Based on SigenStor 16-24kW Modbus register map. Target file: src/pymodbus_client.py

Acceptance criteria:

  • pymodbus_client.py implements ModbusTcpClient with connect/disconnect
  • Register read methods for battery SoC, power, inverter status, PV production
  • Returns structured data (dict) from each read cycle
  • Error handling for connection timeout and modbus exceptions
  • Unit test stub with mocked responses

Project: sigenstor-control Tags: [sigenstor, phase1, pymodbus]

Note (2026-06-29T19:57:29Z)

Picked up by ralph at 2026-07-12T10:30:00+00:00. Plan: research Sigenergy SigenStor Modbus register map, create pymodbus config/implementation.