Supported device types and versions
Communication line configuration
Communication station configuration
I/O tag configuration
Literature
Document revisions
The protocol supports reading and writing data with LG's proprietary serial (2-wire RS-485 bus) PI-485 protocol. This protocol is used by LG air conditioners and heat pumps for communication.
The protocol has been deployed to communicate with the LG Therma V heat pump (HU071MR U44).
Required line parameters:
Configuration dialog box - tab „Parameters".
They influence some optional parameters of the protocol.
Table 2
| Full name | Meaning | Unit | Default value |
|---|---|---|---|
| A retry count of the request in case of a communication failure. | - | 1 | |
| The delay between request retry in case of a communication failure. | ms | 0 milliseconds | |
| The delay after sending the request before reading the response. | ms | 100 milliseconds | |
| The delay between response readings till its completing. | ms | 100 milliseconds | |
| Retry count of response reading till its completing. | - | 4 | |
| Activating the passive mode. In this mode, no requests are sent, only messages read from the bus are processed. The passive mode is used for reading data if there is another master on the bus (e.g. communication converter to Modbus protocol - LG PI485 Gateway). | YES/NO | NO |
For further information on protocol parameters, see the topic Communication line - configuration dialog box.
Possible I/O tag types: Ai, Ao, Ci, Co, Di, Dout, Qi
The address of the I/O tag is textual. The following table shows a list of existing addresses:
| Address | I/O tag type | Description |
|---|---|---|
| LOCK_REMOTE | Dout | Set the remote controller functionality: Lock (1) / Unlock (0). |
| LOCK_REMOTE_RD | Di | Get the remote controller functionality: Lock (1) / Unlock (0). |
| OPERATE_OUTPUT | Dout | Set the device functionality: the device is stopped (0) / working (1). |
| OPERATE_OUTPUT_RD | Di | Get the device functionality: the device is stopped (0) / working (1). |
| OPERATE_DHW | Dout | Set the domestic hot water heating in the built-in boiler: disabled (0) / enabled (1). |
| OPERATE_DHW_RD | Di | Get the domestic hot water heating in the built-in boiler: disabled (0) / enabled (1). |
| OPERATE_MODE | Ao | Set the mode of operation: 0=cooling, 1=dehumidification, 2=ventilation, 3=auto, 4=heating. |
| OPERATE_MODE_RD | Ai | Get the mode of operation: 0=cooling, 1=dehumidification, 2=ventilation, 3=auto, 4=heating. |
| TEMP_OUTPUT_SP | Ao | Set the desired outlet water temperature. |
| TEMP_OUTPUT_RD | Ai | Get the desired outlet water temperature. |
| TEMP_DHW_SP | Ao | Set the desired temperature of the domestic water in the built-in boiler. |
| TEMP_DHW_RD | Ai | Get the desired temperature of the domestic water in the built-in boiler. |
| TEMP_WATER_IN | Ai | Current inlet water temperature. |
| TEMP_WATER_OUT | Ai | Current outlet water temperature. |
| TEMP_ROOM | Ai | Current room temperature (external sensor connectable to the indoor heat pump unit). |
| TEMP_TANK | Ai | The current temperature of the domestic water in the built-in boiler. |
| TEMP_SOLAR | Ai | The current temperature of an optional external solar system (if connected). |
| CONNECTED_IDU | Di | The indoor unit is connected (1) or disconnected (0). |
| TGT_TEMP_SEL | Di | The current setpoint is the temperature of air TEMP_ROOM (0) or water TEMP_OUTPUT_SP (1). |
Note: Temperatures are integer numbers (°C).
Note: it takes longer to set the values (approx. 12 seconds).
Example: TEMP_OUTPUT_SP has a value of 40 °C. After writing a value of 42, only after approx. 12 seconds does the value of the I/O tag TEMP_OUTPUT_RD change to 42.