Mitsubishi Electric
Japanese VRF air conditioning — KNX integration via MAC-397IF Modbus adapter for commercial multi-split systems.
Mitsubishi Electric (Tokyo, Japan — founded 1921) is one of the world's leading manufacturers of VRF (Variable Refrigerant Flow) air conditioning systems, sold under the City Multi and Mr. Slim brands across Europe. In KNX building automation projects, Mitsubishi Electric equipment integrates via two principal paths: the PAC-IF010B-E direct KNX interface for single indoor units, and the MAC-397IF-E Modbus adapter for multi-unit commercial VRF systems where a single M-NET RS-485 bus serves up to 50 indoor units. KNX integrators use Mitsubishi VRF in commercial offices, hotels, and high-end residential projects where simultaneous zone-by-zone temperature setpoint control, fan speed adjustment, and operating mode switching (heat/cool/fan/dry/auto) must be managed from KNX group addresses. The SRK wall-mount and SLZ-M ceiling cassette series cover residential and light commercial applications, while the PUMY and PURY outdoor VRF units address large commercial floors.
Role in our panels
How we use Mitsubishi Electric
The MAC-397IF-E adapter converts Mitsubishi's proprietary M-NET protocol (RS-485 physical layer, 9600 baud) into standard Modbus RTU RS-485, allowing any Modbus TCP gateway — such as Wago 750-363, HMS Anybus X-Gateway, or Schneider Modicon — to bridge between the Mitsubishi M-NET bus and KNX group addresses. One MAC-397IF-E handles up to 50 indoor units, each mapped to a unique Modbus register block: register pairs for room temperature (read), setpoint (read/write), operating mode (0=auto, 1=heat, 2=dry, 3=cool, 4=fan), fan speed (auto/low/medium/high), and on/off status. For single-room residential installations, the PAC-IF010B-E provides native KNX TP connectivity to one indoor unit without any intermediate gateway — ETS6 parameterization assigns group addresses directly to DPT 9.001 for temperature setpoint and DPT 5.001 for operating mode. Panel wiring for MAC-397IF-E setups requires a shielded twisted-pair RS-485 cable from the Mitsubishi M-NET bus header to the adapter, a separate Modbus RTU RS-485 cable to the gateway, and Ethernet for Modbus TCP into the KNX logic processor.
In PanelCraft panels for Mitsubishi Electric projects, the wiring design differs by integration path. For PAC-IF010B-E installations: 24V SELV power supply in panel feeds the PAC-IF010B-E; KNX TP bus connects directly to the interface; the interface mounts in the indoor unit terminal block area (not in the main panel). For MAC-397IF-E multi-unit setups: shielded RS-485 from the Mitsubishi outdoor unit M-NET header runs to the adapter (terminate with 120-ohm resistor); adapter Modbus RTU RS-485 output runs to a Modbus TCP gateway mounted on DIN-rail in the panel; the gateway connects to the KNX logic controller (e.g., MDT IP Interface or Gira X1) via Ethernet. One MAC-397IF-E on M-NET RS-485 bus connects to the Modbus gateway which writes KNX group addresses for all zones simultaneously — setpoint per zone, mode per zone, on/off per zone — enabling full KNX-controlled HVAC for a 50-unit commercial floor from a single adapter.
Used in these project types
Mitsubishi Electric products
Key components we install
Mitsubishi MAC-397IF-E Modbus Adapter
Converts Mitsubishi M-NET RS-485 proprietary bus to Modbus RTU RS-485. Supports up to 50 indoor units on one M-NET segment. Each indoor unit maps to a unique Modbus register block: setpoint, operating mode, fan speed, on/off, room temperature read-back, filter sign, error code. Requires external Modbus TCP gateway (Wago, Schneider, HMS) to bridge Modbus RTU to KNX group addresses. Essential for commercial VRF projects with multiple zones on KNX.
Mitsubishi PAC-IF010B-E KNX Interface
Native KNX TP bus interface for one Mitsubishi indoor unit. ETS6 application supports DPT 9.001 for temperature setpoint, DPT 5.001 for operating mode (0=auto, 1=heat, 2=dry, 3=cool, 4=fan), DPT 1.001 for on/off. No intermediate gateway required. Mounts in indoor unit terminal box. Draws 24V from panel SELV supply. For residential KNX projects: one PAC-IF010B-E per room with individual split unit.
Mitsubishi SRK25ZS-W Wall-Mount Split 2.5kW
2.5kW (9000 BTU) wall-mounted room air conditioner. R32 refrigerant. A+++ energy rating. Connects to SUZ outdoor unit. Integrates via PAC-IF010B-E for KNX room-by-room temperature control. Used in high-end residential KNX projects where each bedroom or living room requires independent AC zone with KNX weekly schedule, occupancy-based setback, and visualisation on Gira or Siemens panels.
Mitsubishi SLZ-M50FA Ceiling Cassette 5kW
5kW 4-way ceiling cassette indoor unit for VRF systems. Flush-mounts into suspended ceiling tile grid. R410A or R32 via City Multi outdoor. 4-way airflow louvers provide uniform room coverage. Connects to MAC-397IF-E on M-NET bus in commercial projects. Common in open-plan offices, meeting rooms, and hotel suites with KNX zone control — cassette per zone, setpoint and mode from KNX occupancy and time schedule.
Mitsubishi PURY-EP200YLM Commercial VRF Outdoor 20kW
20kW nominal cooling capacity commercial VRF outdoor unit. R410A. Up to 18 indoor units connectable. M-NET bus from this unit serves all connected indoor units — MAC-397IF-E on the M-NET header exposes all zones to KNX via Modbus TCP gateway. For commercial office floors: PURY outdoor + SLZ cassettes per meeting room + MAC-397IF-E + gateway = full KNX zone HVAC control without BACnet license required.
Mitsubishi Electric FAQ
How does KNX connect to Mitsubishi split AC units?
There are two integration paths depending on project scale. For a single indoor unit, the PAC-IF010B-E provides native KNX TP bus connectivity — it mounts in the indoor unit terminal block and connects directly to the KNX bus. ETS6 parameterization assigns group addresses to DPT 9.001 for temperature setpoint, DPT 5.001 for operating mode (0=auto, 1=heat, 2=dry, 3=cool, 4=fan), and DPT 1.001 for on/off. For multiple units on a VRF system, the MAC-397IF-E adapter converts the Mitsubishi M-NET proprietary RS-485 bus to Modbus RTU RS-485; a Modbus TCP gateway (Wago 750-363 or HMS Anybus) then bridges all Mitsubishi register data to KNX group addresses. The MAC-397IF-E path supports up to 50 indoor units from a single adapter, making it the preferred approach for commercial office or hotel projects.
What is the difference between M-NET and Modbus RTU for Mitsubishi VRF?
M-NET is Mitsubishi Electric's proprietary serial bus protocol used internally between outdoor VRF units, indoor units, and system controllers — it uses RS-485 physical layer but the data encoding is closed and not published for third-party use. Modbus RTU RS-485 is an open industrial standard with publicly documented register maps, supported by virtually every industrial gateway, SCADA, and KNX controller. The MAC-397IF-E adapter sits on the M-NET bus, decodes the proprietary protocol, and re-exposes all indoor unit parameters as standard Modbus RTU holding registers — setpoint in register 0x0003, operating mode in 0x0004, and so on. Once the MAC-397IF-E translates M-NET to Modbus RTU, any standard Modbus TCP gateway can read and write these registers and map them to KNX group addresses using the gateway's built-in mapping tool. This architecture means the KNX integrator never needs access to Mitsubishi protocol documentation — only standard Modbus register tables published by Mitsubishi for the MAC-397IF-E.
Can Mitsubishi VRF integrate with BACnet for commercial BMS projects?
Yes — the MAC-397IF-E also natively supports BACnet MS/TP (EIA-485) as an alternative protocol output to Modbus RTU, configurable via DIP switches on the adapter. In large commercial projects, the common architecture is: MAC-397IF-E on M-NET bus outputting BACnet MS/TP → Schneider EcoStruxure Building Operation or Siemens Desigo CC BMS via BACnet IP router for central HVAC management; simultaneously, KNX provides room-level control via KNX room thermostats, occupancy sensors, and time schedules, with a KNX-BACnet gateway (Loytec LINX, Intesis IN-BAC-KNX) exchanging setpoints between the two networks. This split-protocol design is standard in European Grade A commercial buildings: BACnet for the mechanical plant and energy reporting, KNX for room comfort and lighting, with Mitsubishi VRF bridging both via the MAC-397IF-E adapter.
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