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Energy meter · Modbus register map
Eastron SDM630-DI Modbus register map
Updated 16 October 2026
The SDM630-DI is a three-phase, direct-connected (up to 100 A) DIN-rail energy meter with two digital inputs and an RS485 Modbus RTU port. Live readings and energy totals are IEEE-754 floats in input registers (function 04); configuration is held as floats in holding registers (function 03 read, 16 write). This map covers per-phase and total electrical values, demand, THD, import/export energy per phase, and the RS485/demand/system settings.
This page lists 101 Modbus registers for the Eastron SDM630-DI — 9 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
- SDM630-DI
- Equipment type
- Energy meter
- Registers
- 101 (9 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 DI
Integration notes: Eastron SDM630-DI
Read floats with function 04 starting at 0x0000 (two registers per value, high word first). Total power is at 0x0034, import/export kWh at 0x0048/0x004A. Settings are floats in holding registers and need the password written to the KPPA register first for key parameters.
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 | L1 voltage (L-N) | FLOAT32 ABCD | L1 voltage | Read |
| IR 6 | L1 current | FLOAT32 ABCD | L1 current | Read |
| IR 52 | Total active power | FLOAT32 ABCD | Total active power | Read |
| IR 62 | Total power factor | FLOAT32 ABCD | Total power factor | Read |
| IR 70 | Frequency | FLOAT32 ABCD | Frequency | Read |
| IR 72 | Import active energy | FLOAT32 ABCD | Import kWh | Read |
| IR 74 | Export active energy | FLOAT32 ABCD | Export kWh | Read |
Enable Modbus control & writes
Modbus RTU is always active on the RS485 terminals. To change key settings over Modbus, first write the meter password (default 1000) as a float to 40015 (KPPA); reading 40015 returns 1 when authorized.
Byte order & addressing
- Every setting, including enumerations like baud rate, is a 32-bit float spanning two registers; write both registers with function 16.
- Some holding registers use six-digit Modicon numbers (461457, 464515...) that map to hex 0xF010, 0xFC02 and so on.
- Power factor carries a sign for current direction: positive for forward current, negative for reverse.
Network setup
- Default RS485 settings: address 1, 9600 bps, 8 data bits, no parity, 1 stop bit.
- Address, baud, parity and stop bits can be set from the front-panel setup menu or the holding registers listed here.
- Set the system type (1P2W / 3P3W / 3P4W) to match the wiring; the table shows which values each system provides.
Watch out for
- The Int32 and Int64 copies of the readings (310021 onwards) are not mapped because their word order is not documented; use the float registers.
- Max demand and DI counters are cleared with the Reset register (0xF010) codes 0 and 6.
Eastron SDM630-DI 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 | L1 voltage (L-N) | FLOAT32 | ABCD | V | Read | |||
| IR | 2doc 30003 | L2 voltage (L-N) | Not provided on 1P2W or 3P3W wiring. | FLOAT32 | ABCD | V | Read | ||
| IR | 4doc 30005 | L3 voltage (L-N) | Not provided on 1P2W or 3P3W wiring. | FLOAT32 | ABCD | V | Read | ||
| IR | 6doc 30007 | L1 current | FLOAT32 | ABCD | A | Read | |||
| IR | 8doc 30009 | L2 current | FLOAT32 | ABCD | A | Read | |||
| IR | 10doc 30011 | L3 current | FLOAT32 | ABCD | A | Read | |||
| IR | 12doc 30013 | L1 active power | FLOAT32 | ABCD | W | Read | |||
| IR | 14doc 30015 | L2 active power | FLOAT32 | ABCD | W | Read | |||
| IR | 16doc 30017 | L3 active power | FLOAT32 | ABCD | W | Read | |||
| IR | 18doc 30019 | L1 apparent power | FLOAT32 | ABCD | VA | Read | |||
| IR | 20doc 30021 | L2 apparent power | FLOAT32 | ABCD | VA | Read | |||
| IR | 22doc 30023 | L3 apparent power | FLOAT32 | ABCD | VA | Read | |||
| IR | 24doc 30025 | L1 reactive power | FLOAT32 | ABCD | VAr | Read | |||
| IR | 26doc 30027 | L2 reactive power | FLOAT32 | ABCD | VAr | Read | |||
| IR | 28doc 30029 | L3 reactive power | FLOAT32 | ABCD | VAr | Read | |||
| IR | 30doc 30031 | L1 power factor | Sign follows current direction: negative means reverse flow. | FLOAT32 | ABCD | Read | |||
| IR | 32doc 30033 | L2 power factor | Sign follows current direction: negative means reverse flow. | FLOAT32 | ABCD | Read | |||
| IR | 34doc 30035 | L3 power factor | Sign follows current direction: negative means reverse flow. | FLOAT32 | ABCD | Read | |||
| IR | 36doc 30037 | L1 phase angle | FLOAT32 | ABCD | Degrees | Read | |||
| IR | 38doc 30039 | L2 phase angle | FLOAT32 | ABCD | Degrees | Read | |||
| IR | 40doc 30041 | L3 phase angle | FLOAT32 | ABCD | Degrees | Read | |||
| IR | 42doc 30043 | Average L-N voltage | 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 active power | FLOAT32 | ABCD | W | Read | |||
| IR | 56doc 30057 | Total apparent power | FLOAT32 | ABCD | VA | Read | |||
| IR | 60doc 30061 | Total reactive power | FLOAT32 | ABCD | VAr | Read | |||
| IR | 62doc 30063 | Total power factor | Sign follows current direction: negative means reverse flow. | FLOAT32 | ABCD | Read | |||
| IR | 66doc 30067 | Total system phase angle | FLOAT32 | ABCD | Degrees | Read | |||
| IR | 70doc 30071 | Frequency | FLOAT32 | ABCD | Hz | Read | |||
| IR | 72doc 30073 | Import active energy | FLOAT32 | ABCD | kWh | Read | |||
| IR | 74doc 30075 | Export active energy | FLOAT32 | ABCD | kWh | Read | |||
| IR | 76doc 30077 | Import reactive energy | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 78doc 30079 | Export reactive energy | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 80doc 30081 | Apparent energy | FLOAT32 | ABCD | kVAh | Read | |||
| IR | 82doc 30083 | Ah | Accumulated ampere-hours. | FLOAT32 | ABCD | Ah | Read | ||
| IR | 84doc 30085 | Total active power demand | Footnoted as 'import – export' in the manual; see notes. | FLOAT32 | ABCD | W | Read | ||
| IR | 86doc 30087 | Max total active power demand | Footnoted as 'import – export' in the manual; see notes. | FLOAT32 | ABCD | W | Read | ||
| IR | 100doc 30101 | Apparent power demand | FLOAT32 | ABCD | VA | Read | |||
| IR | 102doc 30103 | Apparent power max demand | FLOAT32 | ABCD | VA | Read | |||
| IR | 104doc 30105 | Neutral current demand | 3P4W only. | FLOAT32 | ABCD | A | Read | ||
| IR | 106doc 30107 | Max neutral current demand | 3P4W only. | FLOAT32 | ABCD | A | Read | ||
| IR | 108doc 30109 | Reactive power demand | Footnoted as 'import – export' in the manual; see notes. | FLOAT32 | ABCD | VAr | Read | ||
| IR | 110doc 30111 | Reactive power max demand | Footnoted as 'import – export' in the manual; see notes. | FLOAT32 | ABCD | VAr | Read | ||
| IR | 200doc 30201 | L1-L2 voltage | FLOAT32 | ABCD | V | Read | |||
| IR | 202doc 30203 | L2-L3 voltage | FLOAT32 | ABCD | V | Read | |||
| IR | 204doc 30205 | L3-L1 voltage | FLOAT32 | ABCD | V | Read | |||
| IR | 206doc 30207 | Average L-L voltage | FLOAT32 | ABCD | V | Read | |||
| IR | 224doc 30225 | Neutral current | 3P4W only. | FLOAT32 | ABCD | A | Read | ||
| IR | 234doc 30235 | L1 voltage THD (L-N) | FLOAT32 | ABCD | % | Read | |||
| IR | 236doc 30237 | L2 voltage THD (L-N) | FLOAT32 | ABCD | % | Read | |||
| IR | 238doc 30239 | L3 voltage THD (L-N) | FLOAT32 | ABCD | % | Read | |||
| IR | 240doc 30241 | L1 current THD | FLOAT32 | ABCD | % | Read | |||
| IR | 242doc 30243 | L2 current THD | FLOAT32 | ABCD | % | Read | |||
| IR | 244doc 30245 | L3 current THD | FLOAT32 | ABCD | % | Read | |||
| IR | 248doc 30249 | Average L-N voltage THD | FLOAT32 | ABCD | % | Read | |||
| IR | 250doc 30251 | Average line current THD | FLOAT32 | ABCD | % | Read | |||
| IR | 258doc 30259 | L1 current demand | FLOAT32 | ABCD | A | Read | |||
| IR | 260doc 30261 | L2 current demand | FLOAT32 | ABCD | A | Read | |||
| IR | 262doc 30263 | L3 current demand | FLOAT32 | ABCD | A | Read | |||
| IR | 264doc 30265 | Max L1 current demand | FLOAT32 | ABCD | A | Read | |||
| IR | 266doc 30267 | Max L2 current demand | FLOAT32 | ABCD | A | Read | |||
| IR | 268doc 30269 | Max L3 current demand | FLOAT32 | ABCD | A | Read | |||
| IR | 334doc 30335 | L1-L2 voltage THD | 3P3W only. | FLOAT32 | ABCD | % | Read | ||
| IR | 336doc 30337 | L2-L3 voltage THD | 3P3W only. | FLOAT32 | ABCD | % | Read | ||
| IR | 338doc 30339 | L3-L1 voltage THD | 3P3W only. | FLOAT32 | ABCD | % | Read | ||
| IR | 340doc 30341 | Average L-L voltage THD | 3P3W only. | FLOAT32 | ABCD | % | Read | ||
| IR | 342doc 30343 | Total kWh | Import plus export active energy. | FLOAT32 | ABCD | kWh | Read | ||
| IR | 344doc 30345 | Total kVArh | Import plus export reactive energy. | FLOAT32 | ABCD | kVArh | Read | ||
| IR | 346doc 30347 | L1 import kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 348doc 30349 | L2 import kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 350doc 30351 | L3 import kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 352doc 30353 | L1 export kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 354doc 30355 | L2 export kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 356doc 30357 | L3 export kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 358doc 30359 | L1 total kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 360doc 30361 | L2 total kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 362doc 30363 | L3 total kWh | FLOAT32 | ABCD | kWh | Read | |||
| IR | 364doc 30365 | L1 import kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 366doc 30367 | L2 import kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 368doc 30369 | L3 import kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 370doc 30371 | L1 export kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 372doc 30373 | L2 export kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 374doc 30375 | L3 export kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 376doc 30377 | L1 total kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 378doc 30379 | L2 total kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 380doc 30381 | L3 total kVArh | FLOAT32 | ABCD | kVArh | Read | |||
| IR | 10314doc 310315 | CO2 | Accumulated CO2 emissions figure. | FLOAT32 | ABCD | Kg | Read | ||
| HR | 0doc 40001 | Demand time | Elapsed minutes of the first demand interval; demand readings are valid after one full period. | FLOAT32 | ABCD | min | Read | ||
| HR | 2doc 40003 | Demand period | 0 to 60 minutes; 0 updates demand every second. Default 60. | FLOAT32 | ABCD | min | Read/write | ||
| HR | 10doc 40011 | System type | Wiring system. Default 3P4W. | FLOAT32 | ABCD | Read/write | 1 = 1P2W; 2 = 3P3W; 3 = 3P4W | ||
| HR | 14doc 40015 | Key parameter programming authorization (KPPA) | Read 0/1 authorization state; write the password to unlock key settings. | FLOAT32 | ABCD | Read/write | 0 = Not authorized; 1 = Authorized | ||
| HR | 18doc 40019 | Parity / stop bits | RS485 framing. Default one stop bit, no parity. | 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 | Node address 1 to 247. Default 1. | FLOAT32 | ABCD | Read/write | |||
| HR | 24doc 40025 | Password | Range 0000 to 9999. Default 1000. | FLOAT32 | ABCD | Read/write | |||
| HR | 28doc 40029 | Baud rate | Default 9600. | FLOAT32 | ABCD | Read/write | 0 = 2400; 1 = 4800; 2 = 9600; 3 = 19200; 4 = 38400; 6 = 115200 | ||
| HR | 60doc 40061 | Backlight time | 0 to 121; 0 keeps backlight on, 121 keeps it off. Default 60. | FLOAT32 | ABCD | min | Read/write | ||
| HR | 61456doc 461457 | Reset | Write a code to clear stored values. | UINT16 | Write | 0 = Reset maximum demand; 6 = Reset DI counts | |||
| HR | 64514doc 464515 | Meter code | Model identification code (hex). | UINT16 | Read | ||||
| HR | 64644doc 464645 | Software version | High byte and low byte form version XX.YY. | UINT16 | Read | ||||
| HR | 64646doc 464647 | Program number | Firmware program identifier (hex). | UINT16 | Read |
Notes on this map
- Word order: the manual states that Eastron sends floats big-endian with the first register holding the high 16 bits, and its worked example returns 42 70 00 00 for 60.0. All floats here are ABCD.
- The register table marks each input value as available or not for each wiring system (3P4W, 3P3W, 1P2W); the per-register descriptions repeat this where a value is not available on every system.
- Left out: the Int32 (0.1 V, 0.001 A, 0.1 W ...) and Int64 (Wh, VArh) mirror blocks from 310021 onwards. The manual states big-endian order only for floats, not for these integer types, so their word order is not confirmed by the document.
- Left out: 30255 'Total system power factor' because the table gives its unit as Degrees, which conflicts with 30063 (total power factor) and is likely an error in the source.
- Left out: DI-1/DI-2 counters (40770/40772) and the serial number (464513), which are unsigned 32-bit integers with no stated word order; and the CO2 rate setting (40071), whose 'hex' data format is not defined.
- The int64 CO2 at 310311 is omitted for the same reason; the float CO2 at 310315 is kept.
- Left out: DI filter time (40769). The register table gives its range in milliseconds while the setup-menu section gives the same 0-255 range in minutes, so the unit is ambiguous.
- Demand footnote: the manual says the power-sum demand is calculated for 'import – export' (en dash) without saying whether that means net import minus export or both directions combined; check on a live meter if the sign matters.
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 SDM630-DI
What Modbus registers does the Eastron SDM630-DI have?
This map lists 101 registers: 88 input registers, 13 holding registers. 9 of them can be written. Registers vary with firmware, options and configuration, so confirm against the device.
Are the Eastron SDM630-DI 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 3xxxxx / 4xxxxx for high addresses) next to the hex start address actually sent. Wire address = printed number minus 30001 or 40001 (or 300001 / 400001); e.g. 30001 is 0x0000 and 461457 is 0xF010.
What byte order does the Eastron SDM630-DI 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 SDM630-DI?
Start with IR 0 L1 voltage (L-N) (L1 voltage); IR 6 L1 current (L1 current); IR 52 Total active power (Total active power); IR 62 Total power factor (Total power factor); IR 70 Frequency (Frequency); IR 72 Import active energy (Import kWh); IR 74 Export active energy (Export kWh).
How do I enable Modbus control of the Eastron SDM630-DI?
Modbus RTU is always active on the RS485 terminals. To change key settings over Modbus, first write the meter password (default 1000) as a float to 40015 (KPPA); reading 40015 returns 1 when authorized.
Where is the official Eastron SDM630-DI Modbus documentation?
The source is SDM630-DI User Manual (V1.02 (cover reads 2025 V1.01)), revision 2025-08-04, published free by Eastron at https://www.eastrongroup.com/eastrongroup/2025/08/06/eastronsdm630-diusermanualv1.02.pdf.
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Source: SDM630-DI User Manual · V1.02 (cover reads 2025 V1.01) · rev. 2025-08-04. Register numbers, types, scaling and units are reproduced as published; descriptions are our own.