Do the SDM220 and SDM230 use the same registers?

The core measurements do. Voltage, current, power, power factor, phase angle, frequency and the import, export and total energy counters sit at the same addresses in Eastron's SDM230 protocol and in the mbmd register list for the SDM220.

What baud rate should I set?

Whatever the meter shows at start-up. An SDM230 ships at 9600 bit/s and supports up to 38400 bit/s. An SDM220 ships at 2400 bit/s and tops out at 9600 bit/s.

What does the total active energy register count?

It follows the measurement mode in holding register F920 hex: import plus export by default, import only, or import minus export. Check the mode before you bill from the total.

Why does the meter return an exception?

Every value is two registers, so a request must ask for an even number of registers, and no more than 30 values at once. An odd count or a longer request returns an exception.

Can the SDM230 be used for billing?

The MID version is certified under the Measuring Instruments Directive with certificate 0120/SGS0206, Class B for active energy, and works at 50 Hz only.

Eastron SDM220/230 Modbus register map with EpiSensor Edge

Compatibility

Compatible with EpiSensor Edge over Modbus RTU.

Connect its RS-485 port to a Modbus Interface or to a serial interface on the Gateway. Edge polls it with its Modbus client.

Edge reads 24 values from it, listed under Interface.

Connect it with

Modbus Interface ZMB-3X
From €399 ex VAT Configure Modbus Interface
Gateway ZGW-20
From €899 ex VAT Configure Gateway

Specifications

The SDM220-Modbus and SDM230-Modbus are single-phase, two-wire energy meters in 36 mm DIN-rail housings, connected directly to circuits up to 100 A. Both measure voltage, current, active, apparent and reactive power, power factor and frequency, keep import, export and total counters for active and reactive energy, and record maximum power demand. The SDM230 adds resettable energy counters and a running-hours counter.^2, 3

Power: Self-powered from the measured supply. Draws less than 2 W and 10 VA from the circuit it measures.²
Nominal voltage: 230 V AC, 176 to 276 V operating range²
Current (SDM220): 5(100) A direct connected³
Current (SDM230): 10(100) A direct connected²
Active energy accuracy: Class 1 (IEC 62053-21); Class B (EN 50470-1/3)²
Reactive energy accuracy: Class 2 (IEC 62053-23)²
Voltage and current accuracy: 0.5 %²
Legal metrology (SDM230): MID B+D certified, certificate 0120/SGS0206; 50 Hz for MID⁴
Baud rate (SDM220): 1200, 2400, 4800 or 9600 bit/s, default 2400³
Baud rate (SDM230): 1200 to 38400 bit/s, default 9600²
RS-485 bus (SDM230): Up to 64 meters and 1,000 m per bus⁴
Pulse outputs: Two passive outputs: one configurable, one fixed at 1000 imp/kWh²
Dimensions (SDM220): 36 × 92 × 65 mm (W × H × D)³
Dimensions (SDM230): 36 × 100 × 63 mm (W × H × D)²
Protection: IP51, indoor use²
Operating temperature: -25 to 55 °C, 0 to 95 % RH non-condensing²

Where it is used

Solar PV generation, export and battery storage metering on single-phase supplies, from the import, export and net energy counters.
Solar PV monitoring
Tenant and departmental submetering up to 100 A, with the MID-certified SDM230 where a billing-grade kWh reading is needed.
Tenant submetering and cost allocation
Single-phase EV charger metering for load management.
EV charging load management

Interface

This register map applies to the SDM220-Modbus and SDM230-Modbus.

Communication settings

Protocol: Modbus RTU over two-wire RS-485
Unit address: 1 to 247, default 1
Baud rate: 1200, 2400, 4800 or 9600 bit/s, default 9600 on the SDM230
Parity and stop bits: None, even or odd parity with 1 stop bit, or no parity with 2 stop bits; default no parity, 1 stop bit
Read functions: FC04 for measurements, FC03 for settings; FC16 writes one setting per message
Request size: An even number of registers, up to 30 values (60 registers)
Read with: FC04 (input registers)
Word order: High word first on every value
Addresses: Zero-based PDU addresses, as sent on the bus

From SDM230Modbus protocol V1.1¹.

Register map

Download

Point	Address	Hex	Format	Scale	Unit
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	°
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
Total Power Demand	84	`0x0054`	FLOAT32	×1	W
Maximum Total Power Demand	86	`0x0056`	FLOAT32	×1	W
Import Power Demand	88	`0x0058`	FLOAT32	×1	W
Maximum Import Power Demand	90	`0x005A`	FLOAT32	×1	W
Export Power Demand	92	`0x005C`	FLOAT32	×1	W
Maximum Export Power Demand	94	`0x005E`	FLOAT32	×1	W
Current Demand	258	`0x0102`	FLOAT32	×1	A
Maximum Current Demand	264	`0x0108`	FLOAT32	×1	A
Total Active Energy	342	`0x0156`	FLOAT32	×1	kWh
Total Reactive Energy	344	`0x0158`	FLOAT32	×1	kVArh
Resettable Total Active Energy	384	`0x0180`	FLOAT32	×1	kWh
Resettable Total Reactive Energy	386	`0x0182`	FLOAT32	×1	kVArh

Download the SDM220-Modbus / SDM230-Modbus register map as CSV

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.

Model	Connection	Points	Version	Updated	Download
SDM220-Modbus / SDM230-Modbus	Modbus RTU over two-wire RS-485	24	1.0.0	23 Sep 2026	Download

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

Use the template in Edge

Import the JSON file
On the target Gateway in Edge, open Settings, then Device Templates. Choose Import and select the downloaded JSON file. Confirm that the model and template name match your device.
Load the map for your meter
In the Modbus device wizard, choose the site connection and unit ID, then use Load Template to select the imported map. For an existing device, apply the template to that exact model. Its connection, unit ID and enable state are retained.
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

Check the model
Only the Modbus versions have the RS-485 port: SDM220-Modbus, SDM230-Modbus and the dual-tariff SDM230-2T. The SDM230-Mbus speaks M-Bus and the SDM230-Pulse has pulse outputs only.⁵
Wire the bus
Daisy-chain the A and B terminals of every meter with screened twisted-pair cable, A to A and B to B, and fit a 120 Ω resistor at each end of the line.¹
Set the address and speed on an SDM230
Hold Enter for 3 seconds, enter the password (1000 by default), then set a unique address from 1 to 247, the baud rate and the parity. The defaults are address 1, 9600 bit/s and no parity.²
Match Edge on an SDM220
An SDM220 ships at 2400 bit/s, not 9600. Set the Edge Modbus client to the address, baud rate and parity shown on the meter's display at start-up.³
Read one register
Import the Edge template and read Voltage at input register 0, two registers from an even address. Compare it with the display before you enable the rest of the map.¹

Before you rely on the decode

The addresses are Eastron's 30001-style register numbers less 30001, so Voltage (30001) is address 0 and Total Active Energy (30343) is address 342.

Every value is a 32-bit IEEE 754 float in two registers, most significant register first, which is the meter's default. The template sets Edge to big-endian bytes with no word or byte swap. A holding register can reverse the register order, so compare a steady voltage with the display first.

The map comes from the SDM230 protocol. The SDM220 register list in the mbmd driver matches it for addresses 0 to 78, 342 and 344; check the demand and resettable energy registers on an SDM220 before you rely on them.

Total Active Energy follows the meter's measurement mode: import plus export by default, or import only, or import minus export.

Common questions

Do the SDM220 and SDM230 use the same registers?: The core measurements do. Voltage, current, power, power factor, phase angle, frequency and the import, export and total energy counters sit at the same addresses in Eastron's SDM230 protocol and in the mbmd register list for the SDM220.^1, 6
What baud rate should I set?: Whatever the meter shows at start-up. An SDM230 ships at 9600 bit/s and supports up to 38400 bit/s. An SDM220 ships at 2400 bit/s and tops out at 9600 bit/s.^2, 3
What does the total active energy register count?: It follows the measurement mode in holding register F920 hex: import plus export by default, import only, or import minus export. Check the mode before you bill from the total.¹
Why does the meter return an exception?: Every value is two registers, so a request must ask for an even number of registers, and no more than 30 values at once. An odd count or a longer request returns an exception.¹
Can the SDM230 be used for billing?: The MID version is certified under the Measuring Instruments Directive with certificate 0120/SGS0206, Class B for active energy, and works at 50 Hz only.⁴

Related devices

Sources

SDM230Modbus protocol V1.1 (opens in a new tab) (PDF) Eastron
SDM230-Modbus user manual V1.8 (opens in a new tab) (PDF) Eastron
SDM220-Modbus user manual V2.0 (opens in a new tab) (PDF) Eastron
SDM230 series DIN rail mounted, single phase, 100A datasheet (opens in a new tab) (PDF) Eastron
SDM230M series product page (opens in a new tab) Eastron Europe
SDM220 register driver (opens in a new tab) mbmd
Eastron SDM220/230 device template (opens in a new tab) evcc · revision 8160673647fb
Eastron SDM220/230 register driver (opens in a new tab) mbmd · revision eef6045ae30e