Eastron SDM630-Modbus

Three-phase energy meter

The SDM630-Modbus V2 is a direct-connected three-phase meter with an RS-485 Modbus RTU port and two pulse outputs. Edge reads its measurements through a ZMB-31 or a serial interface on the Gateway.

Eastron SDM630-Modbus V2
  • Modbus RTU

Three-phase energy meter

Download Edge template

Compatibility

Compatible through Modbus RTU

Eastron publishes a Modbus RTU protocol document for the SDM630-Modbus V2, an RS-485 meter. Edge reads its measurements over that serial link.

This page covers the direct-connected SDM630-Modbus V2 over RS-485. The SDM630-TCP, SDM630-Mbus, pulse-only, dual-tariff and SDM630MCT versions are separate products with their own interfaces, wiring and register maps.

Connect it with

Route into Edge

For a remote meter where a wireless bridge avoids a new long data-cable route

  • Modbus
  • Wireless
  • Edge
  • Platforms
Three-phase energy meter
Interface
Gateway
Edge
Output
SDM630-ModbusSDM630-Modbus RS-485
ZMB-31Modbus RTU to the EpiSensor wireless network
ZGW-20 GatewayHosts Edge locally
EpiSensor EdgeModbus client + register map
Customer platformMQTT · API · files
Modbus RTU · RS-485
EpiSensor wireless
Runs locally
Optional onward data
Connect the meter's two-wire RS-485 bus to a ZMB-31, keep the address and serial settings already set on the meter, and read only the measurement registers in Edge. If another controller already polls the bus, agree the change with its owner first. The customer-platform output is optional; Edge remains the local system of record.

When the Gateway has an isolated RS-485 serial interface

  • Modbus
  • Edge
  • Platforms
Three-phase energy meter
Interface
Gateway
Edge
Output
SDM630-ModbusSDM630-Modbus RS-485
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
Use the address, baud rate, parity and stop bits already set on the meter. A Modbus TCP to RTU gateway can reach it over a network, but the meter itself stays a Modbus RTU device. The customer-platform output is optional; Edge remains the local system of record.

Specifications

A direct-connected DIN-rail meter: the load current passes through the meter, up to 100 A per phase, so no current transformers are needed. It measures voltage, current, power, power factor, frequency and energy on all three phases and totals.12

Connection
Direct, up to 100 A per phase; 1P2W, 3P3W or 3P4W2
Communications
RS-485 Modbus RTU, plus two pulse outputs13
Power supply
From the voltage inputs2
Protection
IP51 front; 4 kV insulation, 6 kV impulse withstand; CAT III; EN 61326-1 EMC2
Mounting
DIN rail, indoor panel1

Interface

This register map is for the SDM630-Modbus V2. SDM630-TCP, SDM630-Mbus and SDM630MCT have their own interfaces and are not covered here.

Communication settings

Interface
RS-485 Modbus RTU, two pulse outputs, direct connection up to 100 A
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
ZMB-31 wireless bridge or an approved direct serial interface

From SDM630Modbus Smart Meter Modbus Protocol Implementation V1.83.

Register map

Download
PointAddressHexFormatScaleUnit
Voltage L1-N 0 0x0000 FLOAT32 ×1 V
Voltage L2-N 2 0x0002 FLOAT32 ×1 V
Voltage L3-N 4 0x0004 FLOAT32 ×1 V
Current L1 6 0x0006 FLOAT32 ×1 A
Current L2 8 0x0008 FLOAT32 ×1 A
Current L3 10 0x000A FLOAT32 ×1 A
Active Power L1 12 0x000C FLOAT32 ×1 W
Active Power L2 14 0x000E FLOAT32 ×1 W
Active Power L3 16 0x0010 FLOAT32 ×1 W
Power Factor L1 30 0x001E FLOAT32 ×1 -
Power Factor L2 32 0x0020 FLOAT32 ×1 -
Power Factor L3 34 0x0022 FLOAT32 ×1 -
Total Active Power 52 0x0034 FLOAT32 ×1 W
Total Apparent Power 56 0x0038 FLOAT32 ×1 VA
Total Reactive Power 60 0x003C FLOAT32 ×1 VAr
Total Power Factor 62 0x003E FLOAT32 ×1 -
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
Neutral Current 224 0x00E0 FLOAT32 ×1 A

Download the SDM630-Modbus V2 register map as CSV

Assessment

This page covers the SDM630-Modbus V2 (RS-485). The TCP, M-Bus, pulse-only, dual-tariff and MCT versions have their own register maps.

InteroperabilityWell supported
Eastron publishes the full Modbus RTU map: function codes, zero-based addresses, data types and units.134
AccuracySupported with conditions
A full three-phase measurement set. Which values it reports depends on the wiring mode (1P2W, 3P3W or 3P4W). This page covers the direct-connected SDM630-Modbus V2 only.123
SecurityLimited
Front-panel settings are password protected. Modbus RTU has no authentication or encryption, so keep the RS-485 bus inside the panel and on a network you control.124
ReliabilitySupported with conditions
Powered from its voltage inputs. 4 kV insulation, 6 kV impulse withstand, EN 61326-1 EMC, CAT III. Eastron does not say how the meter recovers after a bus fault, so test a reconnect at commissioning.12
RuggednessSupported with conditions
A DIN-rail meter with an IP51 front, for an indoor panel. Mount it in an enclosure that suits the location.12
ScalabilitySupported with conditions
Multi-drop RS-485 with one master per bus. Bus length, termination and the polling interval set how many meters one bus can carry.13
LifecycleSupported with conditions
A current product with a published protocol document and manual. Keep the document revision you commissioned against with the Edge template.123

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
SDM630-Modbus V2 RS-485 Modbus RTU, two pulse outputs, direct connection up to 100 A 22 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 phase 1 line-to-neutral voltage

Use Eastron’s V1.8 map as a best-effort starting point on a 1P2W or 3P4W installation: reference 30001 maps to wire address 0. For 3P3W use line 1-to-line 2 voltage, reference 30201, wire address 200, with the same FC04/two-register float32 read.

Function
FC04 Read Input Registers
Document reference
30001
PDU start
0 (0x0000)
Length
2 registers
Decode
IEEE-754 float32; verify normal (high word first) or reversed register order against the meter display
Engineering unit
V, multiplier 1, offset 0
Independent decoder example
A simulated 230.0 V value is words 0x4366, 0x0000 in normal order, or 0x0000, 0x4366 in reversed order. Bytes within each word remain most significant first.
Read request PDU
04 00 00 00 02. Add the actual meter address and RTU CRC through the Modbus client; this is not a complete serial frame.
3P3W alternative PDU
04 00 C8 00 02: FC04, line 1-to-line 2 voltage at offset 200, two registers in V

Acceptance: The example verifies the decoder, not the physical meter. Compare several fresh phase 1 readings with the front panel at the same time, then record the working word order. Never change the meter’s register order just to make an imported template appear correct.

  1. Identify the model

    Check the front label says SDM630-Modbus V2 and note the firmware on the display. Have a qualified electrician confirm the wiring mode (1P2W, 3P3W or 3P4W): the phase 1 voltage check does not apply to 3P3W.

  2. Set the address and serial settings

    Note the address, baud rate, parity and stop bits already set on the meter rather than assuming defaults. If another controller polls the bus, agree any change with its owner first.

  3. Wire and terminate the bus

    Check RS-485 polarity, the common reference, bias and termination along the whole bus. A communication check never justifies changing live panel wiring. Keep one active Modbus master on the serial segment; a second poller can corrupt otherwise correct reads.

  4. Check one value

    For 1P2W or 3P4W, read phase 1 line-to-neutral voltage with FC04 at PDU address 0, quantity 2. For 3P3W, use line 1-to-line 2 voltage at address 200 (0x00C8), quantity 2. Compare the float32 value with the display and select the matching normal or reversed word order in Edge. Leave meter settings and counters unchanged.

  5. Import the template

    Import the Edge template for the rest of the map. Treat a missing or stale reading as invalid, never as zero.

Common questions

Does the SDM630-Modbus need current transformers?
No. It is direct-connected up to 100 A per phase. For higher currents Eastron sells the SDM630MCT family, which uses 1 A or 5 A transformers and has its own documents.1
Which Modbus function code reads the measurements?
Use FC04 for the measurement input registers. Each measurement occupies two registers as IEEE-754 float32. The protocol supports normal and reversed register order, so confirm the installed setting with a known live value instead of assuming high word first. The 30001 document reference is PDU address 0.3
Why are some phase readings missing on a 3P3W installation?
In 3P3W mode the meter has no neutral reference, so the phase-to-neutral values are marked unavailable in the protocol document. Read the line values and totals instead.23
Can the same template be used for SDM630MCT or SDM630-TCP?
Use the template for the exact model. MCT models measure through external current transformers and TCP models have a different connection path. Matching a few register addresses does not establish matching input ratings, serial settings or every measurement.23

Sources

  1. SDM630-Modbus V2 product page (opens in a new tab) Eastron
  2. SDM630-Modbus V2 User Manual, cover 2023 V1.5 (opens in a new tab) (PDF) Eastron
  3. SDM630Modbus Smart Meter Modbus Protocol Implementation V1.8 (opens in a new tab) (PDF) Eastron Europe
  4. Modbus specifications and implementation guides (opens in a new tab) Modbus Organization

Further reading

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