MBMap Registry
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  2. Alfen
  3. Eve (NG9xx)

Alfen Eve (NG9xx) Modbus register map

Also covers Eve Single, Eve Double

EV charging station on the NG9xx platform, Modbus TCP

  • Official
  • 92 registers
  • Modbus TCP
  • Revision 2 · 2026-11-10
  • Identity: 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.

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Communication

Protocol
Modbus TCP
Unit ID
1
TCP port
502
Byte / word order
CDAB · bytes big-endian, words low first (word swap)
Addresses
1-based · wire address = address − 1
Max read
125 registers per request

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

Map

Registers
92 holding registers
Groups
6
Translation tables
5
Revision
2 · 2026-11-10
Added
()
File
maps/alfen/eve.mbmap.json · 20 KB · history
SHA-256
596662b2716d7e0fb3b753415f0ece6efa73d71d5b9521f6c4b85ad0e85c7465
Manufacturer
alfen.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
RoleRegisterAddressTypeValues
Firmware Firmware version holding 123 string[17]
Serial number Station serial number holding 157 string[11]

Sources and notes

Source: Alfen ICU B.V., Modbus for ACE, Configuration Guide, version 1.0, 05/2025

  • Every register is a holding register (function 3 to read, 6 and 16 to write). The manual numbers them from 1 and says to subtract 1 for the address on the wire, so the numbers here are 1-based (address_base 1).
  • Which device answers depends on the Modbus server address: 200 for the station registers (1100 to 1105) and the smart charging network registers (1400 to 1431); 1 for the single socket, or the left socket of a dual socket station; 2 for the right socket. The socket registers (300 to 425 and 1200 to 1215) are read from server address 1 or 2. The manual does not say which address reaches the product identification and date registers (100 to 178). The default unit_id here is 1 (a socket).
  • 32-bit values are mixed-endian: bytes inside a 16-bit word are big-endian and the low word comes first (word_order little). The manual says this only for 32-bit values; the 64-bit values (energy, uptime, meter timestamp) are given the same word order here, which the manual does not state.
  • A 32-bit value must be read or written in one request, not as two requests. A write to a multi-register value that does not cover all its registers is refused.
  • A reserved or unavailable register is returned as NaN (0xFFFF for a 16-bit register). Chargers with a Reallin meter made after 2021 return NaN for the sum registers of current, apparent power, reactive power and real energy consumed; older chargers with an ABB meter return numbers.
  • Strings hold two ASCII characters per register and end with a zero.
  • Modbus TCP is off by default. It needs the Active Load Balancing licence, and the settings Allow reading, Allow writing maximum currents, Enable sockets and Enable Smart Charging Network must be set in the ACE Service Installer (version 4.0 or later). Up to two clients can connect at the same time. UDP is not supported.
  • The maximum current registers (1210 and 1417 to 1422) are not kept across a reboot. After the valid time (60 s by default) without a new write the charger falls back to its safe current, so poll more often than the valid time. The safe current must be set before a maximum current can be written.
  • At most 125 registers can be read in one request.
  • Register 1104 (OCPP state) is listed as 1104..1105 in the manual, which overlaps 1105 (number of sockets); it is one register here. The meter state bit field (register 300) and meter type (305) values are as listed in the manual. No registers have the firmware, model or serial role because the manual does not say which server address answers the identification registers.
  • Written from the manufacturer's document; not tested on a device.
AreaAddressNameTypeAccessUnitScaleDescription
HR 100 string[17] R Station name
HR 117 string[5] R
HR 122 int16 R
HR 123 string[17] R
HR 140 string[17] R Platform, for example NG910
HR 157 string[11] R
HR 168 int16 R yr
HR 169 int16 R month
HR 170 int16 R day
HR 171 int16 R h
HR 172 int16 R min
HR 173 int16 R s
HR 174 uint64 CDAB R s ×0.001
HR 178 int16 R min Offset from UTC in minutes
HR 1100 float32 CDAB R A The actual maximum current
HR 1102 float32 CDAB R °C Board temperature, not the ambient temperature
HR 1104 uint16 R Tells whether the back office is connected
HR 1105 uint16 R
HR 1400 string[4] R
HR 1404 uint16 R Number of connected sockets
HR 1405 float32 CDAB R A
HR 1407 float32 CDAB R A
HR 1409 float32 CDAB R A
HR 1411 float32 CDAB R A
HR 1413 float32 CDAB R A
HR 1415 float32 CDAB R A
HR 1417 float32 CDAB RW A Maximum current for each phase, written by the energy management system
HR 1419 float32 CDAB RW A Maximum current for each phase, written by the energy management system
HR 1421 float32 CDAB RW A Maximum current for each phase, written by the energy management system
HR 1423 uint32 CDAB R s
HR 1425 uint32 CDAB R s
HR 1427 uint32 CDAB R s
HR 1429 float32 CDAB R A Configured SCN safe current
HR 1431 uint16 R
HR 1200 uint16 R
HR 1201 string[5] R IEC 61851 state, see the manual's Mode 3 state listing
HR 1206 float32 CDAB R A Overall maximum current in use for the socket
HR 1208 uint32 CDAB R s Remaining time before the socket falls back to the safe current
HR 1210 float32 CDAB RW A Setpoint written by the energy management system
HR 1212 float32 CDAB R A
HR 1214 uint16 R Whether the written setpoint is used to work out the actual applied max current
HR 1215 uint16 RW
HR 300 bool bit 0 R Initialised
HR 300 bool bit 1 R
HR 300 bool bit 2 R
HR 300 bool bit 3 R
HR 301 uint64 CDAB R s ×0.001 Time since the last measurements were received
HR 305 uint16 R
HR 306 float32 CDAB R V
HR 308 float32 CDAB R V
HR 310 float32 CDAB R V
HR 312 float32 CDAB R V
HR 314 float32 CDAB R V
HR 316 float32 CDAB R V
HR 318 float32 CDAB R A
HR 320 float32 CDAB R A
HR 322 float32 CDAB R A
HR 324 float32 CDAB R A
HR 326 float32 CDAB R A Returns NaN on chargers with a Reallin meter made after 2021
HR 328 float32 CDAB R
HR 330 float32 CDAB R
HR 332 float32 CDAB R
HR 334 float32 CDAB R
HR 336 float32 CDAB R Hz
HR 338 float32 CDAB R W
HR 340 float32 CDAB R W
HR 342 float32 CDAB R W
HR 344 float32 CDAB R W
HR 346 float32 CDAB R VA
HR 348 float32 CDAB R VA
HR 350 float32 CDAB R VA
HR 352 float32 CDAB R VA Returns NaN on chargers with a Reallin meter made after 2021
HR 354 float32 CDAB R VAr
HR 356 float32 CDAB R VAr
HR 358 float32 CDAB R VAr
HR 360 float32 CDAB R VAr Returns NaN on chargers with a Reallin meter made after 2021
HR 362 float64 CDAB R Wh
HR 366 float64 CDAB R Wh
HR 370 float64 CDAB R Wh
HR 374 float64 CDAB R Wh
HR 378 float64 CDAB R Wh
HR 382 float64 CDAB R Wh
HR 386 float64 CDAB R Wh
HR 390 float64 CDAB R Wh Returns NaN on chargers with a Reallin meter made after 2021
HR 394 float64 CDAB R VAh
HR 398 float64 CDAB R VAh
HR 402 float64 CDAB R VAh
HR 406 float64 CDAB R VAh
HR 410 float64 CDAB R VArh
HR 414 float64 CDAB R VArh
HR 418 float64 CDAB R VArh
HR 422 float64 CDAB R VArh

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