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  • LG Air Conditioning via PI-485 and LGAP protocol

    TapHome supports direct communication via RS485 (BUS 1, BUS 2 or BUS 3 terminal) with LG air conditioning condensers and split units. This is done by LG PI-485 communication card and by proprietary LGAP communication protocol.

    • Communication via RS485 (Bus) connection.
    • Multiple split units can be fully operated from TapHome with minimal additional cost.
    • PI-485 will be provided directly by your LG supplier

    It is possible to control every split unit separately:

    • On/Off
    • Operation mode (Cooling, Dehumidification, Fan only, Auto, Heating)
    • Thermostat (Set point, Actual temperature)
    • Fan speed (Low, Medium, High, Auto)
    • Vane swing (On, Off)


    LG AC product line

    PI-485 built in

    PI-485 can be added

    Multi V 3

    Multi FDX

    Multi MU3 and higher
    E.g.: MU3M25

    Split 18 and higher

    Multi MU2 E.g. MU2M15, MU2M16, MU2M17



    Connect PI-485 card with outdoor condenser unit

    1. Disable power to System
    2. Connect CN_OUT on the PI‐485 to the CN_CENTRAL on the ODU PCB
    3. Connect BUS_A and BUS_B on the PI‐485 to the LG Central Controller or Gateway
    4. Select proper DIP Switch configuration: 1 and 4 ON, all others OFF

    1. Connect CN_PWR on the PI‐485 to the Outdoor Unit PCB Power Connector
    2. Restore Power to the System

    Make sure that PI-485 card is working properly

    Red LED

    Orange and Yellow LED

    Green RS485 LED

    For more details, see LG PI-485 Installation Manual:

    Connect PI-485 with TapHome

    One or more PI-485 cards can be connected to TapHome BUS terminal. This communication line cannot be combined with TapHome Bus devices, or Modbus RTU devices.


    Assigning addresses to LG split units

    Turn on indoor split unit. To set its unique identification address, you will need to use combination of buttons on infrared remote controller.

    Remove battery on infrared remote control. At the same time, hold "FAN SPEED" button and insert the battery back. Please note, that second button might differ on every model. Alternatively, you can try to use left-top button, "COMFORT AIR", or "MODE" buttons. Once you enter address configuration mode, you can see 2 digits on the display and you can change address by pressing TEMPERATURE UP / DOWN buttons. Confirm your choice with "POWER" button. Remove the battery and put it back again when you are done.

    Please note that LG unit address on remote control is hexadecimal number, while in TapHome configuration, it is decimal number. E.g. number 0A set in LG is translated as number 10 in TapHome, and number 10 in LG is translated as 16 in TapHome.

    Defining LG interface in TapHome

    Open Settings → Hardware → TapHome Bus → Terminals and disable one BUS terminal so that you can use it for communication with LG.

    In Settings → Hardware → Add new interface → LGAC

    Add split units with proper address.