Eastron SDM230-Modbus

Power and energy meter

SDM230-Modbus is a two-module, single-phase meter for direct connection up to 100 A. Read import and export energy separately, match the installed serial settings and decode complete float32 register pairs.

Eastron SDM230-Modbus
  • Modbus RTU

Power and energy meter

Download Edge template

Compatibility

Compatible through Modbus RTU

The manufacturer documents local measurement reads that can be configured in an Edge Modbus client.

SDM230-Modbus RS-485 version covered by the cited series manual and the corrected standard-model protocol (header V1.3; introduction V1.4). SDM230-Std has a reduced display and is excluded from this voltage/display commissioning procedure. Pulse, M-Bus, Wi-Fi and dual-tariff variants need their own interface or configuration scope. The optional 12-point starter requires most-significant-register-first ordering and is read-only with exports disabled; verify the configurable register-order setting before polling.

Connect it with

For the exact RS-485 model identified below

  • Modbus
  • Edge
  • Platforms
Power and energy meter
Interface
Gateway
Edge
Output
SDM230-ModbusSDM230-Modbus RS-485 port
Isolated serial interfaceApproved RS-485-to-host adapter
ZGW-20 GatewayHosts Edge locally
EpiSensor EdgeEdge Modbus client
Customer platformMQTT · API · files
Modbus RTU · RS-485
Isolated serial
Runs locally
Optional onward data
The SDM230-Modbus version provides RS-485. The series manual gives default address 1 and 2400 bit/s, with configurable parity and one or two stop bits. Read the installed settings rather than applying defaults from another Eastron family. The customer-platform output is optional; Edge remains the local system of record.

Specifications

Compared with a one-module SDM120, SDM230 offers a 100 A direct-connected single-phase arrangement in a 36 mm housing. It is not the CT-input SDM630MCT: the load current passes through the meter’s intended terminals, so no external CT ratio belongs in the data conversion. Select the exact wiring version and terminal arrangement from the installed meter’s manual.2

Measurement arrangement
Single-phase,100 A direct connection2
Housing
36 × 99 × 63 mm;35 mm DIN-rail mounting2
Enclosure
IP51 for indoor use2
Serial rates
1200, 2400, 4800 or 9600 bit/s in the cited manual2
Framing and address
None/even/odd parity;1 or 2 stop bits; address 1–2472
Measurement reads
FC04, two-register float32 values; units are specified per entry1

Interface

This register map is for the SDM230-Modbus. SDM230-Std, SDM230-2T and SDM230-Pulse / M-Bus / Wi-Fi have their own interfaces and are not covered here.

Communication settings

Interface
Single-phase 100 A direct connection, RS-485 Modbus RTU
Interface
RS-485 Modbus RTU; use installed serial settings
Measurement read
FC04, two registers per Float
Ordering
Most significant register first; verify the configurable meter setting
Read with
FC04 (input registers)
Word order
High word first on every value
Addresses
Zero-based PDU addresses, as sent on the bus
Route into Edge
Use this standard single-tariff scope and the installed serial settings.

From Corrected SDM230-Modbus protocol (header V1.3; introduction V1.4)1.

Register map

Download
PointAddressHexFormatScaleUnit
Voltage 0 0x0000 FLOAT32 ×1 V
Current 6 0x0006 FLOAT32 ×1 A
Active power 12 0x000C FLOAT32 ×1 W
Apparent power 18 0x0012 FLOAT32 ×1 VA
Reactive power 24 0x0018 FLOAT32 ×1 VAr
Power factor 30 0x001E FLOAT32 ×1 -
Phase angle 36 0x0024 FLOAT32 ×1 deg
Frequency 70 0x0046 FLOAT32 ×1 Hz
Import active energy 72 0x0048 FLOAT32 ×1 kWh
Export active energy 74 0x004A FLOAT32 ×1 kWh
Import reactive energy 76 0x004C FLOAT32 ×1 kVArh
Export reactive energy 78 0x004E FLOAT32 ×1 kVArh

Download the SDM230-Modbus register map as CSV

Assessment

SDM230-Modbus RS-485 version covered by the cited series manual and protocol V1.1. SDM230-Std has a reduced display and is excluded from this voltage/display commissioning procedure. Pulse, M-Bus, Wi-Fi and dual-tariff variants need their own interface or configuration scope.

InteroperabilityWell supported
A public protocol defines measurement addresses, Float format and configurable register order.1
AccuracySupported with conditions
The single-phase direct100 A arrangement is explicit; installation point determines counter meaning.2
SecurityNot yet assessed
The cited sources do not establish authenticated or encrypted measurement transport.1
ReliabilitySupported with conditions
Complete measurement pairs are documented, but inconsistent bulk-limit text needs firmware-specific qualification.1
RuggednessSupported with conditions
The manual specifies IP51 indoor installation.2
ScalabilitySupported with conditions
Configurable addresses and rates support shared RS-485 polling; large reads need separate verification.2
LifecycleNot yet assessed
No guaranteed support duration or end-of-sale commitment is stated in these sources.2

Edge template

This JSON file supplies the register map. Applying it to an existing meter replaces its sensor list while retaining the site connection, unit ID and enable state.

ModelConnectionPointsVersionUpdatedDownload
SDM230-Modbus Single-phase 100 A direct connection, RS-485 Modbus RTU 12 1.0.0 Download

Downloads need a signed-in account with Edge download access.

Use the template in Edge

  1. Import the JSON file

    In Edge, open Settings, then Devices and Templates. Choose Import JSON and select the downloaded file. Confirm that the model and template name match your device.

  2. Load the map for your meter

    For a new Modbus device, use Load Template before entering the manufacturer or model; it fills those fields and the register list. Set the name, site connection and unit ID, check the polling enable state, then test before saving. For an existing device, apply only to the matching model; this replaces its sensor list but retains its connection, unit ID and enable state.

  3. Test a reading

    Use Test in the wizard and compare a known reading with the meter display. Check its unit, sign and scale, then confirm that timestamps keep advancing. These starter maps are read-only and leave exports off until you configure them.

Setup

Read one voltage pair

The corrected SDM230-Modbus protocol defines voltage at PDU address 0, FC04, Float in V.

Request PDU
04 00 00 00 02
Unit 1 RTU frame
01 04 00 00 00 02 71 CB
Independent decoder example
43 66 00 00 represents 230.0 V with the most significant register first.
Boundary
Read the complete two-register value; do not interpret a single 16-bit response as a Float.

Acceptance: The CRC is independently checked. The voltage bytes are a synthetic example, not a captured device response. Verify register order and display agreement before adding other measurements; this guide does not assert a bulk-read maximum from the inconsistent introductory text.

  1. Identify the standard RS-485 variant

    Check SDM230-Modbus on the meter and record its wiring version. Pulse-only, M-Bus and Wi-Fi models do not gain an RS-485 port from sharing the SDM230 family name. The Std variant has a reduced display and is outside this commissioning procedure.

  2. Match the communication settings

    Read address, speed, parity and stop bits from the installed meter. The manual gives address 1 and 2400 bit/s as defaults. Use a unique address and matching framing before enabling polling.

  3. Request one complete voltage

    Use FC04, PDU address 0 and quantity 2. The display reference 30001 describes the same voltage location; it is not the address transmitted in the PDU.

  4. Verify float ordering and units

    Decode all four bytes with the meter’s configured register order and compare with the display. The corrected protocol permits reversed register order. Active power is W; accumulated energy is kWh. Do not add a CT multiplier to this direct-connected model.

  5. Choose direction deliberately

    Collect import and export counters separately and verify their behaviour under the site’s actual flow. The circuit’s installation point determines whether a counter describes grid exchange, generation or a particular load; the same field name does not identify the installation point.

Common questions

Is SDM230 a CT-connected meter?
The standard model in this guide is100 A direct connected. It should not receive a CT ratio multiplier in Edge. Choose a CT-input meter when the measurement arrangement requires external current transformers.2
Can I use address 30001 directly?
No. Voltage is shown as input reference 30001 but its protocol start address is 0x0000. Send address 0 with FC04 and read two registers.1
Why avoid one-register or very large reads?
A Float needs two 16-bit registers. The corrected standard-model protocol specifies at most 40 values, or 80 registers, per transaction. Start with one complete value and check the display before widening the map. The optional starter keeps its largest block to ten registers.1
Does a separate export counter mean the installation measures solar generation?
Not necessarily. At the grid boundary it records exported energy; on a generator circuit it describes flow at that circuit. Preserve the installation point and direction in the measurement name.1
Does this setup procedure cover SDM230-Std?
No. The series manual shows an energy-focused display sequence for Std, without the voltage/current/power screens used for the acceptance check here. Shared RS-485 terminals do not establish the same display or measurement scope. Use the exact Std documentation and an appropriate reference check for that variant.2

Sources

  1. Corrected SDM230-Modbus protocol (header V1.3; introduction V1.4) (opens in a new tab) (PDF) Eastron Europe
  2. SDM230 series installation and operating manual (opens in a new tab) (PDF) Eastron Europe
  3. SDM230 Modbus protocol V1.1 (opens in a new tab) (PDF) Eastron Europe

Further reading

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