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Energy meter · Modbus register map
Eastron SDM630MCT Modbus register map
Updated 28 October 2026
The SDM630MCT is Eastron's three-phase, CT-connected (1 A / 5 A CT secondary) DIN-rail multifunction meter with an RS485 Modbus RTU port. Every value is a 32-bit IEEE-754 float, high register first: live readings and energy in input registers (function 04) and settings in holding registers (function 03 read, 16 write). This map covers the full input table plus the demand, wiring, RS485, CT/PT ratio, pulse and reset settings.
This page lists 109 Modbus registers for the Eastron SDM630MCT — 12 writable — with the table, 0-based wire address, data type, word order, scale, units and access of each, re-typed from Eastron’s own free documentation (linked below) and checked against it.
- Manufacturer
- Eastron
- Model
- SDM630MCT
- Equipment type
- Energy meter
- Registers
- 109 (12 writable)
- Transport
- Modbus RTU
- Default unit ID
- 1
- Default serial
- 9600 baud, 8N1
- Documented addressing
- Modicon 3xxxx/4xxxx (drop the prefix, subtract 1)
- 32-bit word order
- ABCD high word first (big-endian)
- Also known as
- SDM630 MCT
Integration notes: Eastron SDM630MCT
Use function 04 from 30001 (wire 0) in blocks of up to 60 registers; every value is a big-endian float. Settings are floats in holding registers written with function 16, one parameter per message; system type and CT/PT ratios need the password written to 40025 first.
Minimum registers to map
Addresses are 0-based wire addresses. Enough to monitor and run the unit; map more as the job needs.
| Register | Name | Type | Why | Access |
|---|---|---|---|---|
| IR 0 | Phase 1 line to neutral volts | FLOAT32 ABCD | Phase 1 voltage | Read |
| IR 6 | Phase 1 current | FLOAT32 ABCD | Phase 1 current | Read |
| IR 52 | Total system power | FLOAT32 ABCD | Total system power | Read |
| IR 62 | Total system power factor | FLOAT32 ABCD | Total power factor | Read |
| IR 70 | Frequency of supply voltages | FLOAT32 ABCD | Frequency | Read |
| IR 72 | Total import kWh | FLOAT32 ABCD | Total import kWh | Read |
| IR 74 | Total export kWh | FLOAT32 ABCD | Total export kWh | Read |
| HR 62 | CT ratio | FLOAT32 ABCD | CT ratio check | Read/write |
Enable Modbus control & writes
RS485 Modbus RTU is built in on the RS485 versions. Set address, baud rate and parity/stop bits from the front setup menu or holding registers 40021, 40029 and 40019.
Byte order & addressing
- All values, including settings, are 32-bit floats (ABCD).
- Odd register counts are rejected.
- Power factor sign shows current direction, not leading/lagging.
Network setup
- Defaults: address 1, 9600 baud, no parity, 1 stop bit.
- Baud 2400-38400.
- Terminate both bus ends with 120 ohm; up to 32 nodes and 1200 m per segment.
Watch out for
- CT and PT ratios (40063 / 40065) need the password first and are not settable on MID versions.
- The meter does not answer broadcasts (address 0).
Eastron SDM630MCT Modbus registers
Address = 0-based wire address (the documented number is shown under it when it differs) · Order: ABCD = high word first, CDAB = low word first · Scale: engineering value = raw × scale.
| Table | Address | Name | Description | Type | Order | Scale | Units | Access | Values / bits |
|---|---|---|---|---|---|---|---|---|---|
| IR | 0doc 30001 | Phase 1 line to neutral volts | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | V | Read | ||
| IR | 2doc 30003 | Phase 2 line to neutral volts | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | V | Read | ||
| IR | 4doc 30005 | Phase 3 line to neutral volts | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | V | Read | ||
| IR | 6doc 30007 | Phase 1 current | FLOAT32 | ABCD | A | Read | |||
| IR | 8doc 30009 | Phase 2 current | Not available on single-phase. | FLOAT32 | ABCD | A | Read | ||
| IR | 10doc 30011 | Phase 3 current | Not available on single-phase. | FLOAT32 | ABCD | A | Read | ||
| IR | 12doc 30013 | Phase 1 active power | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | W | Read | ||
| IR | 14doc 30015 | Phase 2 active power | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | W | Read | ||
| IR | 16doc 30017 | Phase 3 active power | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | W | Read | ||
| IR | 18doc 30019 | Phase 1 apparent power | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | VA | Read | ||
| IR | 20doc 30021 | Phase 2 apparent power | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | VA | Read | ||
| IR | 22doc 30023 | Phase 3 apparent power | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | VA | Read | ||
| IR | 24doc 30025 | Phase 1 reactive power | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | VAr | Read | ||
| IR | 26doc 30027 | Phase 2 reactive power | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | VAr | Read | ||
| IR | 28doc 30029 | Phase 3 reactive power | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | VAr | Read | ||
| IR | 30doc 30031 | Phase 1 power factor | Sign shows current direction: negative = reverse. Not available on 3-phase 3-wire. | FLOAT32 | ABCD | Read | |||
| IR | 32doc 30033 | Phase 2 power factor | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | Read | |||
| IR | 34doc 30035 | Phase 3 power factor | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | Read | |||
| IR | 36doc 30037 | Phase 1 phase angle | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | Degrees | Read | ||
| IR | 38doc 30039 | Phase 2 phase angle | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | Degrees | Read | ||
| IR | 40doc 30041 | Phase 3 phase angle | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | Degrees | Read | ||
| IR | 42doc 30043 | Average line to neutral volts | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | V | Read | ||
| IR | 46doc 30047 | Average line current | FLOAT32 | ABCD | A | Read | |||
| IR | 48doc 30049 | Sum of line currents | FLOAT32 | ABCD | A | Read | |||
| IR | 52doc 30053 | Total system power | FLOAT32 | ABCD | W | Read | |||
| IR | 56doc 30057 | Total system volt amps | FLOAT32 | ABCD | VA | Read | |||
| IR | 60doc 30061 | Total system VAr | FLOAT32 | ABCD | VAr | Read | |||
| IR | 62doc 30063 | Total system power factor | Sign shows current direction: negative = reverse. | FLOAT32 | ABCD | Read | |||
| IR | 66doc 30067 | Total system phase angle | FLOAT32 | ABCD | Degrees | Read | |||
| IR | 70doc 30071 | Frequency of supply voltages | FLOAT32 | ABCD | Hz | Read | |||
| IR | 72doc 30073 | Total import kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 74doc 30075 | Total export kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 76doc 30077 | Total import kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 78doc 30079 | Total export kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 80doc 30081 | Total VAh | FLOAT32 | ABCD | kVAh | Read | |||
| IR | 82doc 30083 | Ah | FLOAT32 | ABCD | Ah | Read | |||
| IR | 84doc 30085 | Total system power demand | FLOAT32 | ABCD | W | Read | |||
| IR | 86doc 30087 | Maximum total system power demand | FLOAT32 | ABCD | W | Read | |||
| IR | 100doc 30101 | Total system VA demand | FLOAT32 | ABCD | VA | Read | |||
| IR | 102doc 30103 | Maximum total system VA demand | FLOAT32 | ABCD | VA | Read | |||
| IR | 104doc 30105 | Neutral current demand | Only on 3-phase 4-wire. | FLOAT32 | ABCD | A | Read | ||
| IR | 106doc 30107 | Maximum neutral current demand | Only on 3-phase 4-wire. | FLOAT32 | ABCD | A | Read | ||
| IR | 108doc 30109 | Total system reactive power demand | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | VAr | Read | ||
| IR | 110doc 30111 | Maximum total system reactive power demand | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | VAr | Read | ||
| IR | 200doc 30201 | Line 1 to line 2 volts | Not available on single-phase 2-wire. | FLOAT32 | ABCD | V | Read | ||
| IR | 202doc 30203 | Line 2 to line 3 volts | Not available on single-phase 2-wire. | FLOAT32 | ABCD | V | Read | ||
| IR | 204doc 30205 | Line 3 to line 1 volts | Not available on single-phase 2-wire. | FLOAT32 | ABCD | V | Read | ||
| IR | 206doc 30207 | Average line to line volts | Not available on single-phase 2-wire. | FLOAT32 | ABCD | V | Read | ||
| IR | 224doc 30225 | Neutral current | Only on 3-phase 4-wire. | FLOAT32 | ABCD | A | Read | ||
| IR | 234doc 30235 | Phase 1 L/N volts THD | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | % | Read | ||
| IR | 236doc 30237 | Phase 2 L/N volts THD | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | % | Read | ||
| IR | 238doc 30239 | Phase 3 L/N volts THD | Not available on 3-phase 3-wire or single-phase. | FLOAT32 | ABCD | % | Read | ||
| IR | 240doc 30241 | Phase 1 current THD | FLOAT32 | ABCD | % | Read | |||
| IR | 242doc 30243 | Phase 2 current THD | Not available on single-phase. | FLOAT32 | ABCD | % | Read | ||
| IR | 244doc 30245 | Phase 3 current THD | Not available on single-phase. | FLOAT32 | ABCD | % | Read | ||
| IR | 248doc 30249 | Average line to neutral volts THD | Not available on 3-phase 3-wire. | FLOAT32 | ABCD | % | Read | ||
| IR | 250doc 30251 | Average line current THD | FLOAT32 | ABCD | % | Read | |||
| IR | 258doc 30259 | Phase 1 current demand | FLOAT32 | ABCD | A | Read | |||
| IR | 260doc 30261 | Phase 2 current demand | Not available on single-phase. | FLOAT32 | ABCD | A | Read | ||
| IR | 262doc 30263 | Phase 3 current demand | Not available on single-phase. | FLOAT32 | ABCD | A | Read | ||
| IR | 264doc 30265 | Maximum phase 1 current demand | FLOAT32 | ABCD | A | Read | |||
| IR | 266doc 30267 | Maximum phase 2 current demand | Not available on single-phase. | FLOAT32 | ABCD | A | Read | ||
| IR | 268doc 30269 | Maximum phase 3 current demand | Not available on single-phase. | FLOAT32 | ABCD | A | Read | ||
| IR | 334doc 30335 | Line 1 to line 2 volts THD | Not available on single-phase 2-wire. | FLOAT32 | ABCD | % | Read | ||
| IR | 336doc 30337 | Line 2 to line 3 volts THD | Not available on single-phase 2-wire. | FLOAT32 | ABCD | % | Read | ||
| IR | 338doc 30339 | Line 3 to line 1 volts THD | Not available on single-phase 2-wire. | FLOAT32 | ABCD | % | Read | ||
| IR | 340doc 30341 | Average line to line volts THD | Not available on single-phase 2-wire. | FLOAT32 | ABCD | % | Read | ||
| IR | 342doc 30343 | Total kWh | Import plus export. | FLOAT32 | ABCD | kWh | Read | ||
| IR | 344doc 30345 | Total kVArh | Import plus export. | FLOAT32 | ABCD | kVArh | Read | ||
| IR | 346doc 30347 | L1 import kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 348doc 30349 | L2 import kWh | Not available on single-phase. | FLOAT32 | ABCD | kWh | Read | ||
| IR | 350doc 30351 | L3 import kWh | Not available on single-phase. | FLOAT32 | ABCD | kWh | Read | ||
| IR | 352doc 30353 | L1 export kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 354doc 30355 | L2 export kWh | Not available on single-phase. | FLOAT32 | ABCD | kWh | Read | ||
| IR | 356doc 30357 | L3 export kWh | Not available on single-phase. | FLOAT32 | ABCD | kWh | Read | ||
| IR | 358doc 30359 | L1 total kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 360doc 30361 | L2 total kWh | Not available on single-phase. | FLOAT32 | ABCD | kWh | Read | ||
| IR | 362doc 30363 | L3 total kWh | Not available on single-phase. | FLOAT32 | ABCD | kWh | Read | ||
| IR | 364doc 30365 | L1 import kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 366doc 30367 | L2 import kVArh | Not available on single-phase. | FLOAT32 | ABCD | kVArh | Read | ||
| IR | 368doc 30369 | L3 import kVArh | Not available on single-phase. | FLOAT32 | ABCD | kVArh | Read | ||
| IR | 370doc 30371 | L1 export kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 372doc 30373 | L2 export kVArh | Not available on single-phase. | FLOAT32 | ABCD | kVArh | Read | ||
| IR | 374doc 30375 | L3 export kVArh | Not available on single-phase. | FLOAT32 | ABCD | kVArh | Read | ||
| IR | 376doc 30377 | L1 total kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 378doc 30379 | L2 total kVArh | Not available on single-phase. | FLOAT32 | ABCD | kVArh | Read | ||
| IR | 380doc 30381 | L3 total kVArh | Not available on single-phase. | FLOAT32 | ABCD | kVArh | Read | ||
| IR | 384doc 30385 | Resettable total active energy | FLOAT32 | ABCD | kWh | Read | |||
| IR | 386doc 30387 | Resettable total reactive energy | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 388doc 30389 | Resettable import active energy | FLOAT32 | ABCD | kWh | Read | |||
| IR | 390doc 30391 | Resettable export active energy | FLOAT32 | ABCD | kWh | Read | |||
| IR | 392doc 30393 | Resettable import reactive energy | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 394doc 30395 | Resettable export reactive energy | FLOAT32 | ABCD | kVArh | Read | |||
| HR | 0doc 40001 | Demand time | Minutes into the first demand period; demand values are valid once it reaches the period. | FLOAT32 | ABCD | min | Read | ||
| HR | 2doc 40003 | Demand period | 0, 5, 8, 10, 15, 20, 30 or 60 min (default 60); 0 shows live values. | FLOAT32 | ABCD | min | Read/write | ||
| HR | 10doc 40011 | System type | Needs the password (40025) first. | FLOAT32 | ABCD | Read/write | 1 = 1P2W; 2 = 3P3W; 3 = 3P4W | ||
| HR | 12doc 40013 | Pulse output 1 width | 60, 100 or 200 ms; default 200. | FLOAT32 | ABCD | ms | Read/write | ||
| HR | 14doc 40015 | Password lock | FLOAT32 | ABCD | Read | 0 = Locked; 1 = Unlocked | |||
| HR | 18doc 40019 | Parity / stop bits | Default 0. | FLOAT32 | ABCD | Read/write | 0 = 1 stop bit, no parity; 1 = 1 stop bit, even parity; 2 = 1 stop bit, odd parity; 3 = 2 stop bits, no parity | ||
| HR | 20doc 40021 | Modbus address | 1-247, default 1. | FLOAT32 | ABCD | Read/write | |||
| HR | 22doc 40023 | Pulse 1 divisor | FLOAT32 | ABCD | Read/write | 1 = 0.01 kWh/imp; 2 = 0.1 kWh/imp; 3 = 1 kWh/imp; 4 = 10 kWh/imp; 5 = 100 kWh/imp; 6 = 1000 kWh/imp | |||
| HR | 24doc 40025 | Password | Write the password to unlock protected settings (default 1000 per the table; see notes). | FLOAT32 | ABCD | Read/write | |||
| HR | 28doc 40029 | Baud rate | Default 2 (9600). | FLOAT32 | ABCD | Read/write | 0 = 2400; 1 = 4800; 2 = 9600; 3 = 19200; 4 = 38400 | ||
| HR | 62doc 40063 | CT ratio | Primary / secondary current, 1-2000. Needs the password; non-MID meters only. | FLOAT32 | ABCD | Read/write | |||
| HR | 64doc 40065 | PT ratio | Primary / secondary voltage, 1-2000. Needs the password; non-MID meters only. | FLOAT32 | ABCD | Read/write | |||
| HR | 86doc 40087 | Pulse 1 energy type | Default 39. | FLOAT32 | ABCD | Read/write | 37 = Total kWh; 39 = Total kVArh | ||
| HR | 61456doc 461457 | Reset | Write 0000 to reset maximum demand or 0003 to reset the resettable energy. | UINT16 | Write | ||||
| HR | 64514doc 464515 | Meter code | Reads 0x0079 on this model. | UINT16 | Read | ||||
| HR | 64515doc 464516 | Software version | Hex-coded firmware version. | UINT16 | Read |
Notes on this map
- Hosted by Eastron (Metering) Europe, Eastron's European site.
- Word order: the document says each value is an IEEE-754 float sent most significant register first by default (ABCD). It mentions a 'Register Order' holding register that can change this, but that register is not in the table, so it is not listed.
- Read and write an even number of registers; odd counts return an exception. A request is limited to 30 values (60 registers) per the overview, while the input-register section says 40 parameters; keep requests at 30 values or fewer.
- Each input value is marked available or not per wiring system (3P4W, 3P3W, 1P2W); unavailable values read zero. The descriptions say where a value is missing.
- Left out: 30255 'Total system power factor' because the table gives its unit as Degrees, which clashes with 30063.
- Left out: CT2 and PT2 rows (hex 0034 / 0030), which have no register number in the table; and the serial number (464513), an unsigned 32-bit integer with no stated word order.
- Demand note: the power-sum demand is described as calculated for import minus export; check on a live meter if the sign matters.
- Total kWh / kVArh (30343 / 30345) are import plus export, not net.
- CT type (1 A / 5 A) and DIN-rail mounting are from the SDM630MCT series user manual on eastrongroup.com (https://www.eastrongroup.com/eastrongroup/2024/08/21/eastronsdm630mctseriesusermanual.pdf).
- The password default is printed as 1000 in the holding-register table but as 0000 in the password section; try both.
- The reset register (461457) is a single 2-byte register although the overview says requests must use an even register count; the document does not resolve this.
Check it against the live device. A register map tells you what the controller can expose; the unit in front of you may differ by firmware or options. Read a few registers and compare them with the unit’s own display; for a 32-bit value the float and byte-order decoder shows all four word orders at once, so a wrong word order or scale is obvious. New to this? Read what a register map is and why addresses are off by one.
Questions about the Eastron SDM630MCT
What Modbus registers does the Eastron SDM630MCT have?
This map lists 109 registers: 93 input registers, 16 holding registers. 12 of them can be written. Registers vary with firmware, options and configuration, so confirm against the device.
Are the Eastron SDM630MCT Modbus addresses 0-based or 1-based?
The manufacturer's document numbers registers Modicon 3xxxx/4xxxx (drop the prefix, subtract 1). Every address on this page is the 0-based wire address you put in the request; the documented number is shown under it where it differs. Registers are printed Modicon style (30001 / 40001, and six-digit 46xxxx for high addresses) next to the hex start address actually sent. Wire address = printed number minus 30001 or 40001 (or 400001): 30001 is 0x0000, 30007 is 0x0006 (the document's own example), 461457 is 0xF010.
What byte order does the Eastron SDM630MCT use for 32-bit values?
Multi-register values in this map use ABCD (high word first (big-endian)). Set your client to this order for every 32/64-bit value in the table.
What are the minimum Modbus registers to integrate the Eastron SDM630MCT?
Start with IR 0 Phase 1 line to neutral volts (Phase 1 voltage); IR 6 Phase 1 current (Phase 1 current); IR 52 Total system power (Total system power); IR 62 Total system power factor (Total power factor); IR 70 Frequency of supply voltages (Frequency); IR 72 Total import kWh (Total import kWh); IR 74 Total export kWh (Total export kWh); HR 62 CT ratio (CT ratio check).
How do I enable Modbus control of the Eastron SDM630MCT?
RS485 Modbus RTU is built in on the RS485 versions. Set address, baud rate and parity/stop bits from the front setup menu or holding registers 40021, 40029 and 40019.
Where is the official Eastron SDM630MCT Modbus documentation?
The source is Eastron SDM630MCT Smart Meter Modbus Protocol Implementation V1.7 (V1.7), published free by Eastron at https://www.eastroneurope.com/images/uploads/products/protocol/SDM630MCT_MODBUS_Protocol_V1.7.pdf.
More Eastron Modbus register maps
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Eastron SDM120CT-40mA single-phase CT-connected DIN-rail meter with RS485 Modbus RTU, user manual V1.0 (2026-07-16).
Also known as: SDM120CT-M-40mA, SDM120CT-M 40mA - Energy meter
Eastron SDM230-DI
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Also known as: SDM630 DI
Source: Eastron SDM630MCT Smart Meter Modbus Protocol Implementation V1.7 · V1.7. Register numbers, types, scaling and units are reproduced as published; descriptions are our own.