LG BNU-BAC Owner's Manual page 62

Troubleshooting
- Problem : The TX/RX LED of the LG-NET 1,2,3,4 of the BACnet Gateway is not blinked.
¡ The TX/RX LED blinks if normal.
- Expected cause : The power is not applied to the 485 communication terminal
The RS485 communication polarity is changed
The P1485 DIP switch is not correctly set
The power is not applied to the indoor unit
The address is not correctly set to the indoor unit
- Diagnosis
Is the power is applied
to the P1485?
Is the polarity of the 485
communication connection
line correct?
Is the DIP switch of the
P1485 correctly set?
Is the power applied to
the indoor unit?
Is the power is applied
to the P1485?
Set the address of the indoor unit.
62 BACnet Gateway
YES
YES
YES
YES
NO
NO
Apply the power to the P1485.
NO
Because the 485 communication has
a polarity, the connection should be
correctly done.
NO
Turn on No. 1 and 4 of the DIP switch.
NO
Apply the power to the indoor unit.