ABB M4M 20 / M4M 30 Modbus register map

Also covers M4M 20 Bacnet, M4M 20 Ethernet, M4M 20 I/O, M4M 20 Modbus, M4M 20 Profibus, M4M 20 Rogowski, M4M 20-M ETH, M4M 20-M RTU, M4M 2X ETH, M4M 2X ETH PQ1, M4M 2X ETH PQ1+R, M4M 2X ETH PQ2, M4M 2X ETH PQ2+R, M4M 2X ETH RTS, M4M 2X RTU, M4M 2X RTU PQ1, M4M 2X RTU PQ1+R, M4M 2X RTU PQ2, M4M 2X RTU PQ2+R, M4M 2X RTU RTS, M4M 30 Bacnet, M4M 30 Ethernet, M4M 30 I/O, M4M 30 Modbus, M4M 30 Profibus, M4M 30 Rogowski, M4M 30-M ETH, M4M 30-M RTU, M4M 32 Ethernet, M4M 32 Modbus RTU

M4M network analyzers (M4M 20, M4M 30, M4M 32, M4M 2X), Modbus RTU and Modbus TCP

Official
984 registers
Modbus TCP and RTU
Revision 3 · 2026-10-17
Identity: model, firmware, serial number

Official: Written from the manufacturer's documentation, but not tested on a device yet. Check the map against the manufacturer's documentation before you write to a live device. Tested it? Report a test.

Download .mbmap.json Raw JSON View on GitHub Suggest a correction Report a problem

Communication

Protocol: Modbus TCP and RTU
Unit ID: 1
TCP port: 502
Serial: 9600 8E1 · 9600 baud, 8 data bits, even parity, 1 stop bit defaults
Byte / word order: ABCD · bytes big-endian, words high first
Addresses: 0-based

Connection values are defaults: the device may be configured differently.

Map

Registers: 984 holding registers
Groups: 22
Translation tables: 1
Revision: 3 · 2026-10-17
Added: 2026-10-14 (2026-10-14)
File: maps/abb/m4m.mbmap.json · 188 KB · history
SHA-256: 15f4f0766601d3764e96381846c8b2a2755c3b17c4d34a557b80dd4dd6264750
Manufacturer: abb.com

Device identity

What a tool can read to check that this map fits the connected device (SPEC.md section 4.7). Registers with a role are read like any other register.

Registers
Role	Register	Address	Type	Values
Serial number	Serial number	holding 35072	string[5]
Firmware	Firmware version	holding 35080	string[8]
Model	Product type	holding 35088	uint16	1 = M4M 20 Modbus, 2 = M4M 20 Ethernet, 3 = M4M 20 Bacnet, +27 more

Sources and notes

Modbus protocol map for M4M network analyzers · version v.1.3G, 9AKK107492A7627
Mapping Table and Details sheets
M4M Network analyzers Modbus manual · version 2CSG445050D0201 [V.1.05]

Source: ABB, "Modbus protocol map for M4M network analyzers" v.1.3G (9AKK107492A7627) and "M4M Network analyzers Modbus manual" 2CSG445050D0201 [V.1.05]

ABB M4M 20, M4M 30, M4M 32 and M4M 2X network analyzers; the product column of each register says which models have it.
Addresses are as sent on the bus. FC03 reads, FC16 writes. Multi-register values are big endian, high word first.
Quantities a model does not have read as "invalid": all FFFF for unsigned, the largest positive value for signed.
Logs, energy snapshots, load profile and max/min demand are read through request headers and data blocks; the indexed configuration tables (I/O, alarms, tariff programs, historicals) are set per channel. Both are described in the manual and left out here.
The powers without decimals (from 0xCB1A) need firmware P1.3.10.0 or newer, as does the M2M-compatible table from 0x1000 (not in this map).
Settings that belong together (CT and VT ratios, RTU settings, date and time) are written in one request.

Area	Address	Type	Access	Unit	Scale	Description
HR	20480	uint64 ABCD	R	kWh	×0.01
HR	20484	uint64 ABCD	R	kWh	×0.01
HR	20488	int64 ABCD	R	kWh	×0.01
HR	20492	uint64 ABCD	R	kvarh	×0.01
HR	20496	uint64 ABCD	R	kvarh	×0.01
HR	20500	int64 ABCD	R	kvarh	×0.01
HR	20504	uint64 ABCD	R	kVAh	×0.01
HR	20508	uint64 ABCD	R	kVAh	×0.01
HR	20512	int64 ABCD	R	kVAh	×0.01
HR	20516	uint64 ABCD	R	kg	×0.001	Uses the CO2 conversion factor at 0x8CE0
HR	20532	uint64 ABCD	R		×0.001	Uses the currency conversion factor at 0x8CE2
HR	20848	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20852	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20856	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20860	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20864	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20868	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20880	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20884	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20888	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20892	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20896	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20900	uint64 ABCD	R	kWh	×0.01	M4M 30
HR	20912	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20916	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20920	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20924	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20928	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20932	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20944	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20948	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20952	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20956	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20960	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	20964	uint64 ABCD	R	kvarh	×0.01	M4M 30
HR	21600	uint64 ABCD	R	kWh	×0.01
HR	21604	uint64 ABCD	R	kWh	×0.01
HR	21608	uint64 ABCD	R	kWh	×0.01
HR	21612	uint64 ABCD	R	kWh	×0.01
HR	21616	uint64 ABCD	R	kWh	×0.01
HR	21620	uint64 ABCD	R	kWh	×0.01
HR	21624	int64 ABCD	R	kWh	×0.01
HR	21628	int64 ABCD	R	kWh	×0.01
HR	21632	int64 ABCD	R	kWh	×0.01
HR	21636	uint64 ABCD	R	kvarh	×0.01
HR	21640	uint64 ABCD	R	kvarh	×0.01
HR	21644	uint64 ABCD	R	kvarh	×0.01
HR	21648	uint64 ABCD	R	kvarh	×0.01
HR	21652	uint64 ABCD	R	kvarh	×0.01
HR	21656	uint64 ABCD	R	kvarh	×0.01
HR	21660	int64 ABCD	R	kvarh	×0.01
HR	21664	int64 ABCD	R	kvarh	×0.01
HR	21668	int64 ABCD	R	kvarh	×0.01
HR	21672	uint64 ABCD	R	kVAh	×0.01
HR	21676	uint64 ABCD	R	kVAh	×0.01
HR	21680	uint64 ABCD	R	kVAh	×0.01
HR	21684	uint64 ABCD	R	kVAh	×0.01
HR	21688	uint64 ABCD	R	kVAh	×0.01
HR	21692	uint64 ABCD	R	kVAh	×0.01
HR	21696	int64 ABCD	R	kVAh	×0.01
HR	21700	int64 ABCD	R	kVAh	×0.01
HR	21704	int64 ABCD	R	kVAh	×0.01
HR	23296	uint32 ABCD	R	V	×0.1
HR	23298	uint32 ABCD	R	V	×0.1
HR	23300	uint32 ABCD	R	V	×0.1
HR	23302	uint32 ABCD	R	V	×0.1
HR	23304	uint32 ABCD	R	V	×0.1
HR	23306	uint32 ABCD	R	V	×0.1
HR	23308	uint32 ABCD	R	V	×0.1
HR	23310	uint32 ABCD	R	A	×0.01
HR	23312	uint32 ABCD	R	A	×0.01
HR	23314	uint32 ABCD	R	A	×0.01
HR	23316	uint32 ABCD	R	A	×0.01
HR	23318	uint32 ABCD	R	A	×0.01
HR	23322	int32 ABCD	R	W	×0.01
HR	23324	int32 ABCD	R	W	×0.01
HR	23326	int32 ABCD	R	W	×0.01
HR	23328	int32 ABCD	R	W	×0.01
HR	23330	int32 ABCD	R	var	×0.01
HR	23332	int32 ABCD	R	var	×0.01
HR	23334	int32 ABCD	R	var	×0.01
HR	23336	int32 ABCD	R	var	×0.01
HR	23338	int32 ABCD	R	VA	×0.01
HR	23340	int32 ABCD	R	VA	×0.01
HR	23342	int32 ABCD	R	VA	×0.01
HR	23344	int32 ABCD	R	VA	×0.01
HR	23346	uint16	R	Hz	×0.01
HR	23347	int16	R	°	×0.1
HR	23348	int16	R	°	×0.1
HR	23349	int16	R	°	×0.1
HR	23350	int16	R	°	×0.1
HR	23351	int16	R	°	×0.1
HR	23352	int16	R	°	×0.1
HR	23353	int16	R	°	×0.1
HR	23357	int16	R	°	×0.1
HR	23358	int16	R	°	×0.1
HR	23359	int16	R	°	×0.1
HR	23360	int16	R		×0.001
HR	23361	int16	R		×0.001
HR	23362	int16	R		×0.001

Help improve this map

I tested it on a deviceReport whether it worked, even if you did not write the map.
Suggest a correctionEdit the file on GitHub; it opens a pull request.
Report a problemA wrong address, type, scale or byte order.
Read the formatWhat each key of the file means (SPEC.md).