Device overview
The Eastron SDM230-Modbus is a single-phase, two-module DIN-rail energy meter for sites where a direct-connected 100 A meter is a better fit than a CT-operated monitor. It measures active and reactive energy, current, voltage, power, power factor, frequency and demand, then exposes readings through RS485 Modbus RTU / DLT645 and pulse outputs.
Installation and measurement
The meter is designed for single-phase 1P2W / 1P+N AC systems and mounts on a 35 mm DIN rail. The selected Modbus variant is direct-fed up to 100 A, so it does not need external current transformers or CT-ratio setup.
Communication and integrations
Core readings are local. Eastron documents RS485 Modbus communication and pulse outputs, so no vendor cloud is required for basic monitoring. Home Assistant support is a standards-based Modbus path through a suitable RS485 adapter or gateway, not a native Eastron cloud integration.
Solar and import/export use
Eastron documents bidirectional measurement and use cases including residential, solar PV, EV charging, industrial and utility applications. That makes this meter useful for single-phase import/export visibility and inverter or gateway workflows that expect a simple Modbus energy meter.
Strengths and limits
Strengths include the 100 A direct-connected format, local Modbus access, Class 1.0 / Class B active-energy accuracy, compact DIN-rail footprint and broad Eastron distributor availability. The main limitation is scope: it is a single-phase direct-connected meter, not a three-phase meter or a high-current CT-operated monitor.