TapHome communicates directly with LG air conditioning condensers and split units over RS485 (BUS 1, BUS 2 or BUS 3 terminal) using the LG PI-485 communication card and the proprietary LGAP protocol. Multiple split units can be fully operated from TapHome with minimal additional cost.

LGAP is a native TapHome interface — there is no template to download or import. You connect the PI-485 card over RS485 and add the LGAC interface directly in the app (Settings → Hardware → Add new interface → LGAC). The PI-485 card is supplied directly by your LG dealer.

Each split unit can be controlled separately:

• On / Off
• Operation mode — Cooling, Dehumidification, Fan only, Auto, Heating
• Thermostat — setpoint and actual temperature
• Fan speed — Low, Medium, High, Auto
• Vane swing — On / Off

Compatibility#

Requirements#

• LG PI-485 extension card — models PMNFP14A1 or PMNFP14A0
• 1 available TapHome Bus terminal on the TapHome Core control unit

Wiring#

Connect the PI-485 card with the outdoor condenser unit

1. Disable power to the system
2. Connect CN_OUT on the PI-485 to 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 the proper DIP switch configuration: 1 and 4 ON, all others OFF
5. Connect CN_PWR on the PI-485 to the outdoor unit PCB power connector
6. Restore power to the system

Verify the PI-485 card is working

• Red LED — blinks as many times as the number of connected indoor units, then turns OFF. The cycle repeats every 3 minutes.
• Orange and Yellow LED — blink continuously.
• Green RS485 LED — blinks when the PI-485 receives data from the central controller.

For full details, see the LG PI-485 Installation Manual.

Connect PI-485 with TapHome#

One or more PI-485 cards can be connected to a TapHome BUS terminal.

This communication line cannot be combined with TapHome Bus devices or Modbus RTU devices on the same terminal. Dedicate the BUS terminal to LG communication.

Configuration#

Assigning addresses to LG split units

Turn on the indoor split unit. To set its unique identification address, use a combination of buttons on the infrared remote controller.

Remove the battery from the remote. While holding the FAN SPEED button, insert the battery back. Once in address configuration mode, two digits appear on the display — change the address with the TEMPERATURE UP / DOWN buttons and confirm with POWER.

The LG unit address on the remote is a hexadecimal number, while in TapHome it is decimal. For example, 0A set on the LG remote becomes 10 in TapHome, and 10 on the LG remote becomes 16 in TapHome.

Defining the LGAC interface in TapHome

1. Open Settings → Hardware → TapHome Bus → Terminals and disable one BUS terminal so it can be used for LG communication.
2. Go to Settings → Hardware → Add new interface → LGAC.
3. Add the split units with their proper (decimal) addresses.