MBMap Registry
  1. Devices
  2. LG
  3. PMBUSB00A Modbus gateway (Therma V / Hydrokit)

LG PMBUSB00A Modbus gateway (Therma V / Hydrokit) Modbus register map

Modbus RTU gateway for LG air conditioners, ventilators and Therma V / Hydrokit heat pumps, indoor unit 0

  • Official
  • 17 registers
  • Modbus RTU
  • Revision 1 · 2026-10-18

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 RTU
Unit ID
1
Serial
9600 8N1 · 9600 baud, 8 data bits, none parity, 1 stop bit
Byte / word order
ABCD · bytes big-endian, words high first
Addresses
1-based · wire address = address − 1

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

Map

Registers
3 holding registers, 6 input registers, 3 coils, 5 discrete inputs
Groups
1
Translation tables
1
Revision
1 · 2026-10-18
Added
()
File
maps/lg/pmbusb00a.mbmap.json · 5 KB · history
SHA-256
785fe1d34d8257019f118f01c84bb58573ac2b42263a3eaa68edded30f50f172
Manufacturer
lg.com

Sources and notes

Source: LG MODBUS RTU GATEWAY (PMBUSB00A) leaflet, Modbus gateway memory map, Hydrokit & THERMA V column

  • The gateway talks to up to 16 indoor units on one module (64 with 4 modules). The registers below are those of the indoor unit with central address N = 0: for another unit, coils and discrete inputs are at N x 16 plus the number listed, input and holding registers at N x 20 plus the number listed.
  • The leaflet numbers the registers 1-based (0x01 coil 1, 10001 discrete 1, 30001 input 1, 40001 holding 1), so this map uses address_base 1.
  • Only the Hydrokit and THERMA V column of the leaflet is mapped. For air conditioners and ventilators the same numbers mean other things (fan speed, swing, filter alarm, pipe temperatures, ventilation mode); see the leaflet.
  • Temperatures are in 0.1 degree Celsius steps. Operate mode values: 0 cooling, 3 auto, 4 heating (1 dehumidifying and 2 fan exist only for air conditioners).
  • Serial settings are fixed by the leaflet at 9600 bit/s, no parity, 1 stop bit; the Modbus slave address of the gateway is set on the gateway itself and is not given in the leaflet.
  • Registers not listed in the leaflet column (reserved) are left out. Other Therma V generations and control boards may use different register addresses: check a read against the unit before writing.
AreaAddressNameTypeAccessUnitScaleDescription
CO 1 bool RW 0 = stop, 1 = run
CO 2 bool RW 0 = disable, 1 = enable
CO 4 bool RW 0 = unlock, 1 = lock
DI 1 bool R 0 = disconnected, 1 = connected
DI 2 bool R 0 = normal, 1 = alarm
DI 3 bool R Hydrokit only: 0 = normal, 1 = hot water only
DI 4 bool R 0 = air, 1 = water
DI 5 bool R Hydrokit only: 0 = CH type error, 1 = BC type error
IR 1 uint16 R 0 to 255; see the error table of the product
IR 2 int16 R °C ×0.1
IR 3 int16 R °C ×0.1
IR 4 int16 R °C ×0.1
IR 5 int16 R °C ×0.1
IR 6 int16 R °C ×0.1 AWHP only
HR 1 uint16 RW Hydrokit with middle-temperature DHW and AWHP: 0, 3 or 4; Hydrokit with high-temperature DHW: 3 or 4
HR 2 uint16 RW °C ×0.1 0 to 127 °C, limited by the upper and lower limits set on the remote controller
HR 3 uint16 RW °C ×0.1 0 to 127 °C, limited by the upper and lower limits set on the remote controller

Help improve this map

Esc