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Energy meter · Modbus register map
ABB EQ meter B23 / B24 (Modbus RTU) Modbus register map
Updated 16 October 2026
The B23 and B24 are three-phase DIN-rail kWh meters from ABB's EQ family. Variants with the RS485 port speak Modbus RTU; every value is a holding register addressed in hex as sent on the wire. This map covers total, tariff, per-phase and resettable energy, instantaneous voltages, currents, powers, angles and power factor, I/O, identification, CT and tariff settings and the reset commands.
This page lists 149 Modbus registers for the ABB EQ meter B23 / B24 (Modbus RTU) — 17 writable — with the table, 0-based wire address, data type, word order, scale, units and access of each, re-typed from ABB’s own free documentation (linked below) and checked against it.
- Manufacturer
- ABB
- Model
- EQ meter B23 / B24 (Modbus RTU)
- Equipment type
- Energy meter
- Registers
- 149 (17 writable)
- Transport
- Modbus RTU
- Default unit ID
- Not stated
- Documented addressing
- hexadecimal, 0-based
- 32-bit word order
- ABCD high word first (big-endian)
- Also known as
- B23, B24, EQ B23, EQ B24
Integration notes: ABB EQ meter B23 / B24 (Modbus RTU)
Set the RS485 port to Modbus on the meter's front panel, then read holding registers with function 3 using the hex addresses directly (0x5000 for total active import). All multi-register values are high word first; energy is 64-bit with 2 decimals.
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 |
|---|---|---|---|---|
| HR 20480 | Active import energy | UINT64 ABCD | Total active import energy (kWh, 0.01) | Read |
| HR 20484 | Active export energy | UINT64 ABCD | Total active export energy | Read |
| HR 23296 | Voltage L1-N | UINT32 ABCD | Voltage L1-N | Read |
| HR 23308 | Current L1 | UINT32 ABCD | Current L1 | Read |
| HR 23316 | Active power Total | INT32 ABCD | Total active power (signed, 0.01 W) | Read |
| HR 23340 | Frequency | UINT16 | Frequency | Read |
| HR 23354 | Power factor Total | INT16 | Total power factor | Read |
| HR 35072 | Serial number | UINT32 ABCD | Serial number, a quick comms check | Read |
Enable Modbus control & writes
In the meter menu, open the RS485 communication settings and select the Modbus protocol (the alternative is ABB's EQ-Bus). Then set baud rate, address and parity on the following menu pages.
Byte order & addressing
- Addresses are hex wire addresses; do not apply a 40001 offset.
- Energy values are 4 registers (64-bit) with resolution 0.01; net energies are signed.
- Readable range is 0x1000-0x8EFF; reading outside it gives exception 2. Up to 125 registers per read.
- Unsupported quantities return FFFF (unsigned) or 7FFF... (signed) instead of an exception.
- A write to a register that the meter does not support is silently ignored, so read back to confirm.
Network setup
- Address range 1-247.
- Baud rates offered for Modbus: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200.
- Parity: None, Odd or Even.
- Function codes supported: 3, 6 and 16; broadcast works for 6 and 16.
Watch out for
- Modbus runs over the RS485 port; meters fitted with the M-Bus interface talk M-Bus instead.
- Powers above about 21 MW overflow the 0.01 W registers; use the DMTME block (whole watts) instead.
ABB EQ meter B23 / B24 (Modbus RTU) 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 |
|---|---|---|---|---|---|---|---|---|---|
| HR | 4096doc 1000 | DMTME 3-phase system voltage | DMTME-compatible block, whole units. | UINT32 | ABCD | V | Read | ||
| HR | 4098doc 1002 | DMTME phase voltage L1-N | DMTME-compatible block, whole units. | UINT32 | ABCD | V | Read | ||
| HR | 4100doc 1004 | DMTME phase voltage L2-N | DMTME-compatible block, whole units. | UINT32 | ABCD | V | Read | ||
| HR | 4102doc 1006 | DMTME phase voltage L3-N | DMTME-compatible block, whole units. | UINT32 | ABCD | V | Read | ||
| HR | 4104doc 1008 | DMTME line voltage L1-L2 | DMTME-compatible block, whole units. | UINT32 | ABCD | V | Read | ||
| HR | 4106doc 100A | DMTME line voltage L2-L3 | DMTME-compatible block, whole units. | UINT32 | ABCD | V | Read | ||
| HR | 4108doc 100C | DMTME line voltage L1-L3 | DMTME-compatible block, whole units. | UINT32 | ABCD | V | Read | ||
| HR | 4112doc 1010 | DMTME line current L1 | DMTME-compatible block. | UINT32 | ABCD | mA | Read | ||
| HR | 4114doc 1012 | DMTME line current L2 | DMTME-compatible block. | UINT32 | ABCD | mA | Read | ||
| HR | 4116doc 1014 | DMTME line current L3 | DMTME-compatible block. | UINT32 | ABCD | mA | Read | ||
| HR | 4118doc 1016 | DMTME 3-phase system power factor | DMTME-compatible block; published as PF x 1000. | INT32 | ABCD | × 0.001 | Read | ||
| HR | 4120doc 1018 | DMTME power factor L1 | DMTME-compatible block; published as PF x 1000. | INT32 | ABCD | × 0.001 | Read | ||
| HR | 4122doc 101A | DMTME power factor L2 | DMTME-compatible block; published as PF x 1000. | INT32 | ABCD | × 0.001 | Read | ||
| HR | 4124doc 101C | DMTME power factor L3 | DMTME-compatible block; published as PF x 1000. | INT32 | ABCD | × 0.001 | Read | ||
| HR | 4134doc 1026 | DMTME 3-phase apparent power | DMTME-compatible block, whole units. | UINT32 | ABCD | VA | Read | ||
| HR | 4136doc 1028 | DMTME apparent power L1 | DMTME-compatible block, whole units. | UINT32 | ABCD | VA | Read | ||
| HR | 4138doc 102A | DMTME apparent power L2 | DMTME-compatible block, whole units. | UINT32 | ABCD | VA | Read | ||
| HR | 4140doc 102C | DMTME apparent power L3 | DMTME-compatible block, whole units. | UINT32 | ABCD | VA | Read | ||
| HR | 4142doc 102E | DMTME 3-phase active power | DMTME-compatible block, whole units. | UINT32 | ABCD | W | Read | ||
| HR | 4144doc 1030 | DMTME active power L1 | DMTME-compatible block, whole units. | UINT32 | ABCD | W | Read | ||
| HR | 4146doc 1032 | DMTME active power L2 | DMTME-compatible block, whole units. | UINT32 | ABCD | W | Read | ||
| HR | 4148doc 1034 | DMTME active power L3 | DMTME-compatible block, whole units. | UINT32 | ABCD | W | Read | ||
| HR | 4150doc 1036 | DMTME 3-phase reactive power | DMTME-compatible block, whole units. | UINT32 | ABCD | var | Read | ||
| HR | 4152doc 1038 | DMTME reactive power L1 | DMTME-compatible block, whole units. | UINT32 | ABCD | var | Read | ||
| HR | 4154doc 103A | DMTME reactive power L2 | DMTME-compatible block, whole units. | UINT32 | ABCD | var | Read | ||
| HR | 4156doc 103C | DMTME reactive power L3 | DMTME-compatible block, whole units. | UINT32 | ABCD | var | Read | ||
| HR | 4166doc 1046 | DMTME frequency | DMTME-compatible block. | UINT32 | ABCD | mHz | Read | ||
| HR | 4512doc 11A0 | DMTME current transformer ratio | DMTME-compatible block. | UINT32 | ABCD | Read | |||
| HR | 20480doc 5000 | Active import energy | Total accumulator, 2 decimals. | UINT64 | ABCD | × 0.01 | kWh | Read | |
| HR | 20484doc 5004 | Active export energy | Total accumulator, 2 decimals. | UINT64 | ABCD | × 0.01 | kWh | Read | |
| HR | 20488doc 5008 | Active net energy | Import minus export, signed. | INT64 | ABCD | × 0.01 | kWh | Read | |
| HR | 20492doc 500C | Reactive import energy | Total accumulator, 2 decimals. | UINT64 | ABCD | × 0.01 | kvarh | Read | |
| HR | 20496doc 5010 | Reactive export energy | Total accumulator, 2 decimals. | UINT64 | ABCD | × 0.01 | kvarh | Read | |
| HR | 20500doc 5014 | Reactive net energy | Import minus export, signed. | INT64 | ABCD | × 0.01 | kvarh | Read | |
| HR | 20504doc 5018 | Apparent import energy | Total accumulator, 2 decimals. | UINT64 | ABCD | × 0.01 | kVAh | Read | |
| HR | 20508doc 501C | Apparent export energy | Total accumulator, 2 decimals. | UINT64 | ABCD | × 0.01 | kVAh | Read | |
| HR | 20512doc 5020 | Apparent net energy | Import minus export, signed. | INT64 | ABCD | × 0.01 | kVAh | Read | |
| HR | 20516doc 5024 | Active import CO2 | CO2 equivalent of imported active energy. | UINT64 | ABCD | × 0.001 | kg | Read | |
| HR | 20532doc 5034 | Active import currency | Cost equivalent of imported active energy. | UINT64 | ABCD | × 0.001 | currency | Read | |
| HR | 20848doc 5170 | Active import tariff 1 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 20852doc 5174 | Active import tariff 2 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 20856doc 5178 | Active import tariff 3 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 20860doc 517C | Active import tariff 4 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 20880doc 5190 | Active export tariff 1 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 20884doc 5194 | Active export tariff 2 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 20888doc 5198 | Active export tariff 3 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 20892doc 519C | Active export tariff 4 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 20912doc 51B0 | Reactive import tariff 1 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 20916doc 51B4 | Reactive import tariff 2 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 20920doc 51B8 | Reactive import tariff 3 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 20924doc 51BC | Reactive import tariff 4 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 20944doc 51D0 | Reactive export tariff 1 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 20948doc 51D4 | Reactive export tariff 2 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 20952doc 51D8 | Reactive export tariff 3 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 20956doc 51DC | Reactive export tariff 4 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21600doc 5460 | Active import energy L1 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21604doc 5464 | Active import energy L2 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21608doc 5468 | Active import energy L3 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21612doc 546C | Active export energy L1 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21616doc 5470 | Active export energy L2 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21620doc 5474 | Active export energy L3 | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21624doc 5478 | Active net energy L1 | INT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21628doc 547C | Active net energy L2 | INT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21632doc 5480 | Active net energy L3 | INT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21636doc 5484 | Reactive import energy L1 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21640doc 5488 | Reactive import energy L2 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21644doc 548C | Reactive import energy L3 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21648doc 5490 | Reactive export energy L1 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21652doc 5494 | Reactive export energy L2 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21656doc 5498 | Reactive export energy L3 | UINT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21660doc 549C | Reactive net energy L1 | INT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21664doc 54A0 | Reactive net energy L2 | INT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21668doc 54A4 | Reactive net energy L3 | INT64 | ABCD | × 0.01 | kvarh | Read | ||
| HR | 21672doc 54A8 | Apparent import energy L1 | UINT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21676doc 54AC | Apparent import energy L2 | UINT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21680doc 54B0 | Apparent import energy L3 | UINT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21684doc 54B4 | Apparent export energy L1 | UINT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21688doc 54B8 | Apparent export energy L2 | UINT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21692doc 54BC | Apparent export energy L3 | UINT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21696doc 54C0 | Apparent net energy L1 | INT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21700doc 54C4 | Apparent net energy L2 | INT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21704doc 54C8 | Apparent net energy L3 | INT64 | ABCD | × 0.01 | kVAh | Read | ||
| HR | 21804doc 552C | Resettable active import | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21808doc 5530 | Resettable active export | UINT64 | ABCD | × 0.01 | kWh | Read | ||
| HR | 21812doc 5534 | Resettable reactive import | Manual's Unit column prints 'kWh' (res. 0,01, 4 regs, Unsigned); listed as kvarh. | UINT64 | ABCD | × 0.01 | kvarh | Read | |
| HR | 21816doc 5538 | Resettable reactive export | Manual's Unit column prints 'kWh' (res. 0,01, 4 regs, Unsigned); listed as kvarh. | UINT64 | ABCD | × 0.01 | kvarh | Read | |
| HR | 23296doc 5B00 | Voltage L1-N | UINT32 | ABCD | × 0.1 | V | Read | ||
| HR | 23298doc 5B02 | Voltage L2-N | UINT32 | ABCD | × 0.1 | V | Read | ||
| HR | 23300doc 5B04 | Voltage L3-N | UINT32 | ABCD | × 0.1 | V | Read | ||
| HR | 23302doc 5B06 | Voltage L1-L2 | UINT32 | ABCD | × 0.1 | V | Read | ||
| HR | 23304doc 5B08 | Voltage L3-L2 | UINT32 | ABCD | × 0.1 | V | Read | ||
| HR | 23306doc 5B0A | Voltage L1-L3 | UINT32 | ABCD | × 0.1 | V | Read | ||
| HR | 23308doc 5B0C | Current L1 | UINT32 | ABCD | × 0.01 | A | Read | ||
| HR | 23310doc 5B0E | Current L2 | UINT32 | ABCD | × 0.01 | A | Read | ||
| HR | 23312doc 5B10 | Current L3 | UINT32 | ABCD | × 0.01 | A | Read | ||
| HR | 23314doc 5B12 | Current N | UINT32 | ABCD | × 0.01 | A | Read | ||
| HR | 23316doc 5B14 | Active power Total | Signed; see note on the ~21 MW range limit. | INT32 | ABCD | × 0.01 | W | Read | |
| HR | 23318doc 5B16 | Active power L1 | INT32 | ABCD | × 0.01 | W | Read | ||
| HR | 23320doc 5B18 | Active power L2 | INT32 | ABCD | × 0.01 | W | Read | ||
| HR | 23322doc 5B1A | Active power L3 | INT32 | ABCD | × 0.01 | W | Read | ||
| HR | 23324doc 5B1C | Reactive power Total | Signed; see note on the ~21 MW range limit. | INT32 | ABCD | × 0.01 | var | Read | |
| HR | 23326doc 5B1E | Reactive power L1 | INT32 | ABCD | × 0.01 | var | Read | ||
| HR | 23328doc 5B20 | Reactive power L2 | INT32 | ABCD | × 0.01 | var | Read | ||
| HR | 23330doc 5B22 | Reactive power L3 | INT32 | ABCD | × 0.01 | var | Read | ||
| HR | 23332doc 5B24 | Apparent power Total | Signed; see note on the ~21 MW range limit. | INT32 | ABCD | × 0.01 | VA | Read | |
| HR | 23334doc 5B26 | Apparent power L1 | INT32 | ABCD | × 0.01 | VA | Read | ||
| HR | 23336doc 5B28 | Apparent power L2 | INT32 | ABCD | × 0.01 | VA | Read | ||
| HR | 23338doc 5B2A | Apparent power L3 | INT32 | ABCD | × 0.01 | VA | Read | ||
| HR | 23340doc 5B2C | Frequency | UINT16 | × 0.01 | Hz | Read | |||
| HR | 23341doc 5B2D | Phase angle power Total | Range -180 to +180. | INT16 | × 0.1 | ° | Read | ||
| HR | 23342doc 5B2E | Phase angle power L1 | Range -180 to +180. | INT16 | × 0.1 | ° | Read | ||
| HR | 23343doc 5B2F | Phase angle power L2 | Range -180 to +180. | INT16 | × 0.1 | ° | Read | ||
| HR | 23344doc 5B30 | Phase angle power L3 | Range -180 to +180. | INT16 | × 0.1 | ° | Read | ||
| HR | 23345doc 5B31 | Phase angle voltage L1 | INT16 | × 0.1 | ° | Read | |||
| HR | 23346doc 5B32 | Phase angle voltage L2 | INT16 | × 0.1 | ° | Read | |||
| HR | 23347doc 5B33 | Phase angle voltage L3 | INT16 | × 0.1 | ° | Read | |||
| HR | 23351doc 5B37 | Phase angle current L1 | INT16 | × 0.1 | ° | Read | |||
| HR | 23352doc 5B38 | Phase angle current L2 | INT16 | × 0.1 | ° | Read | |||
| HR | 23353doc 5B39 | Phase angle current L3 | INT16 | × 0.1 | ° | Read | |||
| HR | 23354doc 5B3A | Power factor Total | Range -1.000 to +1.000. | INT16 | × 0.001 | Read | |||
| HR | 23355doc 5B3B | Power factor L1 | Range -1.000 to +1.000. | INT16 | × 0.001 | Read | |||
| HR | 23356doc 5B3C | Power factor L2 | Range -1.000 to +1.000. | INT16 | × 0.001 | Read | |||
| HR | 23357doc 5B3D | Power factor L3 | Range -1.000 to +1.000. | INT16 | × 0.001 | Read | |||
| HR | 23358doc 5B3E | Current quadrant Total | UINT16 | Read | 1 = Quadrant 1; 2 = Quadrant 2; 3 = Quadrant 3; 4 = Quadrant 4 | ||||
| HR | 23359doc 5B3F | Current quadrant L1 | UINT16 | Read | 1 = Quadrant 1; 2 = Quadrant 2; 3 = Quadrant 3; 4 = Quadrant 4 | ||||
| HR | 23360doc 5B40 | Current quadrant L2 | UINT16 | Read | 1 = Quadrant 1; 2 = Quadrant 2; 3 = Quadrant 3; 4 = Quadrant 4 | ||||
| HR | 23361doc 5B41 | Current quadrant L3 | UINT16 | Read | 1 = Quadrant 1; 2 = Quadrant 2; 3 = Quadrant 3; 4 = Quadrant 4 | ||||
| HR | 25344doc 6300 | Output 1 | UINT16 | Read/write | 0 = OFF; 1 = ON | ||||
| HR | 25345doc 6301 | Output 2 | UINT16 | Read/write | 0 = OFF; 1 = ON | ||||
| HR | 35072doc 8900 | Serial number | UINT32 | ABCD | Read | ||||
| HR | 35080doc 8908 | Meter firmware version | ASCII, e.g. 1.0.0; unused bytes are 0. | STRING[16] | Read | ||||
| HR | 35088doc 8910 | Modbus mapping version | High byte = major, low byte = minor version. | UINT16 | Read | ||||
| HR | 35168doc 8960 | Type designation | ASCII, 12 characters including null terminator. | STRING[12] | Read | ||||
| HR | 35335doc 8A07 | Current tariff | Active tariff, 1 to 4. | UINT16 | Read/write | ||||
| HR | 35375doc 8A2F | Power fail counter | UINT16 | Read | |||||
| HR | 35844doc 8C04 | CT ratio numerator | UINT32 | ABCD | Read/write | ||||
| HR | 35848doc 8C08 | CT ratio denominator | UINT32 | ABCD | Read/write | ||||
| HR | 36066doc 8CE2 | Currency conversion factor | UINT32 | ABCD | × 0.01 | Currency/kWh | Read/write | ||
| HR | 36068doc 8CE4 | LED source | UINT16 | Read/write | 0 = Active energy; 1 = Reactive energy | ||||
| HR | 36608doc 8F00 | Reset power fail counter | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36613doc 8F05 | Reset power outage time | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36619doc 8F0B | Reset input counter input 3 | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36620doc 8F0C | Reset input counter input 4 | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36627doc 8F13 | Reset stored state input 3 | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36628doc 8F14 | Reset stored state input 4 | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36635doc 8F1B | Reset resettable active energy import | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36636doc 8F1C | Reset resettable active energy export | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36637doc 8F1D | Reset resettable reactive energy import | Write 1 to reset. | UINT16 | Write | ||||
| HR | 36638doc 8F1E | Reset resettable reactive energy export | Write 1 to reset. | UINT16 | Write |
Notes on this map
- Addresses are printed in hexadecimal exactly as sent on the bus (the manual says not to subtract 40000 or 1). All data is in holding registers, read with function 3 and written with function 6 or 16.
- Multi-register values are big-endian: the most significant byte is the high byte of the lowest register, so 32-bit and 64-bit values are ABCD (high word first).
- Unsupported quantities still answer, but with an 'invalid' marker: FFFF in every register for unsigned values, and the largest positive value (7FFF, 7FFFFFFF ...) for signed values.
- Instantaneous power registers are signed 32-bit with 2 decimals, which caps them near +/-21 MW; for larger systems the manual points to the DMTME-compatible block, which reports whole watts.
- Built from the current manual revision. The 2013 Revision A also listed input states/counters, error/warning/alarm flag words, load-profile and log resets; the current revision no longer lists them, so they are left out.
- Left out: the DMTME-block energy registers (103E, 1040) whose unit is printed as 'Wh*100' / 'VArh*100', which does not make the scaling direction unambiguous.
- Left out: event-log, alarm-configuration, pulse-output and tariff-configuration register groups, which work through selector/header registers or OBIS-coded multi-register fields rather than simple point reads.
- Resettable reactive energy import/export (5534, 5538): the manual's Unit column prints 'kWh' for these two rows, while the quantity name is reactive energy. Size (4 registers), resolution (0,01) and data type (Unsigned) are printed unambiguously and match the other reactive registers, so they are kept and listed as kvarh; the unit is the only misprint.
- The CO2 (5024) and currency (5034) rows show 'kVAh' in the manual's Details column; their Unit column gives kg and currency, which is what is used here.
- Only outputs 1 and 2 (6300, 6301) are listed as Modbus I/O registers; whether they physically exist depends on the article (2 inputs/2 outputs, 1 output, or none). The input counter and stored-state reset commands (8F0B-8F14) are still listed in the manual and are kept.
- The B24 is transformer connected; energy and power values are reported on the primary side using the CT ratio set in 8C04/8C08.
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 ABB EQ meter B23 / B24 (Modbus RTU)
What Modbus registers does the ABB EQ meter B23 / B24 (Modbus RTU) have?
This map lists 149 registers: 149 holding registers. 17 of them can be written. Registers vary with firmware, options and configuration, so confirm against the device.
Are the ABB EQ meter B23 / B24 (Modbus RTU) Modbus addresses 0-based or 1-based?
The manufacturer's document numbers registers hexadecimal, 0-based. 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. The manual prints each start register in hex as it goes on the wire (e.g. 5000 = 0x5000 = 20480 decimal) and explicitly says not to subtract 40000 or 1. Its example frame reads 0x5000 with function 3.
What byte order does the ABB EQ meter B23 / B24 (Modbus RTU) 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 ABB EQ meter B23 / B24 (Modbus RTU)?
Start with HR 20480 Active import energy (Total active import energy (kWh, 0.01)); HR 20484 Active export energy (Total active export energy); HR 23296 Voltage L1-N (Voltage L1-N); HR 23308 Current L1 (Current L1); HR 23316 Active power Total (Total active power (signed, 0.01 W)); HR 23340 Frequency (Frequency); HR 23354 Power factor Total (Total power factor); HR 35072 Serial number (Serial number, a quick comms check).
How do I enable Modbus control of the ABB EQ meter B23 / B24 (Modbus RTU)?
In the meter menu, open the RS485 communication settings and select the Modbus protocol (the alternative is ABB's EQ-Bus). Then set baud rate, address and parity on the following menu pages.
Where is the official ABB EQ meter B23 / B24 (Modbus RTU) Modbus documentation?
The source is B23/B24 User Manual (2CMC485003M0201 Revision E), revision 2025-11-07, published free by ABB at https://search.abb.com/library/Download.aspx?DocumentID=2CMC485003M0201&LanguageCode=en&DocumentPartId=&Action=Launch.
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ABB ACQ580 water and wastewater drive (embedded Modbus RTU)
ACQ580 drives running the ACQ580 pump control program, embedded fieldbus (EFB) Modbus RTU, addressing mode 0 (default); firmware manual 3AXD50000035867 Rev H.
Also known as: ACQ580-01, ACQ580-04, ACQ580-07, ACQ580-31, ACQ580-34, ACQ580 pump control program - Variable frequency drive
ABB ACS355 machinery drive (embedded Modbus RTU)
ACS355 drives with firmware 5.110 or later using the embedded fieldbus (Modbus RTU) over an FMBA-01 adapter on terminal X3 (EIA-485) or the panel port (RS-232).
Also known as: ACS355-01E, ACS355-03E, ACS355-01U, ACS355-03U, ACS355 with FMBA-01 - Variable frequency drive
ABB ACS480 general purpose drive (embedded Modbus RTU)
ACS480 drives running the ACS480 standard control program, embedded fieldbus (EFB) Modbus RTU, addressing mode 0 (default); firmware manual 3AXD50000047399 Rev G.
Also known as: ACS480-04, ACS480 standard control program - Variable frequency drive
ABB ACS580 general purpose drive (embedded Modbus RTU)
ACS580 drives running the ACS580 standard control program, embedded fieldbus (EFB) Modbus RTU, addressing mode 0 (default).
Also known as: ACS580-01, ACS580-04, ACS580-07, ACS580 standard control program - Variable frequency drive
ABB ACS880 industrial drive, primary control program (embedded Modbus RTU)
ACS880 drives running the primary control program (AINLX) 3.4x or later, embedded fieldbus (EFB) Modbus RTU on terminal XD2D, 58.33 Addressing mode = Mode 0 (default).
Also known as: ACS880-01, ACS880-04, ACS880-07, ACS880-11, ACS880-17, ACS880-31, ACS880-37, AINLX, ACS880 primary control program - Energy meter
ABB EQ meter B21 (Modbus RTU)
ABB EQ B21 single-phase 65 A DIN meter with the RS485 interface set to Modbus.
Also known as: B21, EQ B21 - Power meter (network analyzer)
ABB M4M 20 / M4M 30 network analyzer
ABB M4M 20 and M4M 30 network analyzers, Modbus RTU and Modbus TCP versions, map v1.3O; items marked M4M 30 only are absent on M4M 20.
Also known as: M4M 20, M4M 30, M4M 20 Modbus, M4M 30 Modbus, M4M 20 Ethernet, M4M 30 Ethernet, M4M 20 I/O, M4M 30 I/O, M4M 2X, M4M 30-M, M4M 32
Source: B23/B24 User Manual · 2CMC485003M0201 Revision E · rev. 2025-11-07. Register numbers, types, scaling and units are reproduced as published; descriptions are our own.