Midea · Protocol gateway
MD-AC-MBS-1 (Intesis INMBSMID001I000 interface for Midea split and VRF indoor units) Modbus register map
Default configuration
- Protocol
- RS485
- Port
- 502
- Unit ID
- 1
- Addressing
- 0-based
- Byte order
- Big endian
- Word order
- High word first
- Baud rate
- 9600
- Parity
- None
- Data bits
- 8
- Stop bits
- 2
This device has an RS-485 interface. Reach it through a Modbus RTU-to-TCP gateway, configured with the factory serial settings above.
Register map
| Address | Count | Name | Type | Unit | Scale | Access |
|---|---|---|---|---|---|---|
| 0 | 1 | AC unit On/Off Protocol address 0 (PLC 1). 0 = Off, 1 = On. | UInt16 | - | 1 | RW |
| 1 | 1 | AC unit Mode Protocol address 1 (PLC 2). 0 = Auto (default), 1 = Heat, 2 = Dry, 3 = Fan, 4 = Cool. The available modes depend on the indoor unit. | UInt16 | - | 1 | RW |
| 2 | 1 | AC unit Fan speed Protocol address 2 (PLC 3). 0 = Auto (default), 1 = SP1, 2 = SP2, 3 = SP3; the available speeds depend on the indoor unit. | UInt16 | - | 1 | RW |
| 3 | 1 | AC unit Up/Down vane position Protocol address 3 (PLC 4). 0 = Off (default), 10 = Swing. | UInt16 | - | 1 | RW |
| 4 | 1 | AC unit Temperature setpoint Protocol address 4 (PLC 5). -32768 = initialisation value; 17.0-30.0 °C with the factory x10 °C magnitude, or 63-86 °F with the Fahrenheit DIP setting (see 4.5). | Int16 | °C | 0.1 | RW |
| 5 | 1 | AC unit Temperature reference Protocol address 5 (PLC 6). -32768 = initialisation value; the range is set by the indoor unit's manufacturer. | Int16 | °C | 0.1 | R |
| 6 | 1 | Window contact Protocol address 6 (PLC 7). 0 = Closed (default), 1 = Open. | UInt16 | - | 1 | RW |
| 7 | 1 | Interface disablement Protocol address 7 (PLC 8). 0 = INMBSMID001I000 enabled (default), 1 = disabled. Stored in non-volatile memory. | UInt16 | - | 1 | RW |
| 8 | 1 | Remote control disablement Protocol address 8 (PLC 9). 0 = Remote enabled (default), 1 = Remote disabled; blocks the remote controller on the MD-RC bus. Stored in non-volatile memory. | UInt16 | - | 1 | RW |
| 9 | 1 | AC unit operation time Protocol address 9 (PLC 10). 0-65535 hours of 'On' state. Stored in non-volatile memory. | UInt16 | h | 1 | RW |
| 10 | 1 | AC unit alarm status Protocol address 10 (PLC 11). 0 = No alarm condition, 1 = Alarm condition. | UInt16 | - | 1 | R |
| 11 | 1 | Error code Protocol address 11 (PLC 12). 0 = No error active, 65535 = communication error between the interface and the AC unit, anything else = the error table in section 7 of the manual. | UInt16 | - | 1 | R |
| 13 | 1 | Open Window switch-off timeout Protocol address 13 (PLC 14). 0-30 minutes. | UInt16 | min | 1 | RW |
| 14 | 1 | Modbus RTU baud rate Protocol address 14 (PLC 15). Read-back of the DIP-switch setting: 2400, 4800, 9600 (default), 19200, 38400, 57600, 76800 or 115200 bps. | UInt16 | - | 1 | R |
| 15 | 1 | Device's Modbus slave address Protocol address 15 (PLC 16). Read-back of the SW3 DIP-switch address, 1-63; factory 1. | UInt16 | - | 1 | R |
| 21 | 1 | Max number of fan speeds Protocol address 21 (PLC 22). Set by the SW1 DIP switches (2 or 3 speeds). | UInt16 | - | 1 | R |
| 22 | 1 | Indoor unit ambient temperature from external sensor (Modbus side) Protocol address 22 (PLC 23). -32768 = no temperature is being provided by an external sensor; otherwise the value in °C x10 (or °F, or °C x1 per the DIP setting). | Int16 | °C | 0.1 | RW |
| 23 | 1 | AC real temperature setpoint Protocol address 23 (PLC 24). -32768 = initialisation value; 17.0-30.0 °C in the factory x10 °C magnitude. | Int16 | °C | 0.1 | R |
| 49 | 1 | Device ID Protocol address 49 (PLC 50). 0x2200 for the INMBSMID family. | Hex | - | 1 | R |
| 50 | 1 | Software version Protocol address 50 (PLC 51). | UInt16 | - | 1 | R |
| 66 | 1 | Return path temperature Protocol address 66 (PLC 67). -32768 = initialisation value; the range is set by the indoor unit's manufacturer. | Int16 | °C | 0.1 | R |
| 97 | 1 | Block periodic sendings Protocol address 97 (PLC 98). 0 = Non-blocked (default), 1 = Blocked. Stored in non-volatile memory. | UInt16 | - | 1 | RW |
| 99 | 1 | Reset / reboot device Protocol address 99 (PLC 100). Write 1 to reset the interface. | UInt16 | - | 1 | W |
| 2031 | 1 | Capacity Protocol address 2031 (PLC 2032). 1 = INMBSMID001I000 (1 indoor unit). | UInt16 | - | 1 | R |
Read this device live with Modbus Connect, free for Windows, macOS and Linux
Related guides
Notes
Source: Midea vendor document “MD-AC-MBS-1 — Modbus interface for Midea air conditioning units, user's manual”, the Midea edition of HMS/Intesis document INMBSMID---I000 r1.3 EN, hosted by Midea at https://www.midea.es/wp-content/uploads/2021/04/210406_MU_F_CTR_MD-AC-MBS-1-4-8-32-EN.pdf. The hardware is an Intesis INMBSMID interface, which is why the register tables and the manual text carry the Intesis document number. §4.1 and the quick-start list give the factory line settings: 9600 bps, 8 data bits, no parity, 2 stop bits (8N2), slave address 1 (SW3), set by DIP switches SW3/SW4. §4.2.1-4.2.2 are the registers of the single-indoor-unit model INMBSMID001I000; the protocol address column is stored as the wire address (zero_based, the PLC column is the same number +1 as a 4xxxx reference). Temperature registers are °C x10 by default, hence scale 0.1; the Fahrenheit and x1 °C magnitudes are DIP-switch options and the row descriptions say so. Coils and discrete inputs are not exposed by this interface. The multi-indoor-unit models (INMBSMID004/008/032, holding registers 1000 + 20n + x and 2000-block) are a different product and are not claimed here. Note the document's own inconsistency on the temperature magnitude: footnote 2 of 4.2.1 calls the x10 magnitude the default, while Table 4.3 marks the x1 position as the default DIP setting; the temperature rows here use the x10 reading (scale 0.1), which is also what the library's other Intesis-derivative seed (intesis-inmbsmit001-mitsubishi) uses. The manual's inner title page names Frigicoll air conditioners - Frigicoll is the brand this Midea-hosted edition is written for; the order code MD-AC-MBS-1 is the Frigicoll/Intesis code.
Related devices
- MD-AC-MBS-4 / -8 / -32 (Intesis INMBSMID004/008/032 interface for multi-indoor-unit Midea VRF systems)Midea
- iHomeManager (iHM)Sungrow
- INMBSDAI001I000 Daikin domestic AC to Modbus RTU gatewayHMS Networks (Intesis)
- INMBSFGL001I000 – Fujitsu domestic and VRF air conditioners to Modbus RTU gatewayHMS Networks (Intesis)