LG PQNFB17C1 Installation And User Manual page 204

NOTES
192
When the ventilation equipment is displayed as a network error state (code 242) in LG
Web GUI of the ACP BACnet
When the ventilation equipment is displayed as a network error state (code 242) as followed, in Web
GUI, which is the web server program of the ACP BACnet, please check the following categories.
Check if the BUS-A and BUS-B of RS-485 cable are incorrectly connected.
Check if there is a communication defect between the remote controller and the indoor unit.
Check if the PI485 DIP switch is incorrectly set.
Check if the indoor unit address for the central control is not set.
The CH242 (network error) keeps occurring and disappearing in the ACP BACnet controller.
Case of incorrect connection of RS-485 communication line
If each communication line is connected altogether as in the following figure, the communication line
must be separated.
ACP BACnet
Duplicate setting of the indoor unit address
It is the case of two or more indoor units are set with the same address. It may be the case of
several indoor units having the default address 00 by not setting the central control address from the
beginning for some indoor units.
In such case, assign unique address to each indoor unit not to have indoor unit with a duplicate
address.
PI485
PQNFB17C0
BACnet
PI485 PI485 PI485