LG BNU-BAC Installation & Owner's Manual page 18

How to install
(3) Connecting PI485 – BACnet Gateway
1. When connecting two or more PI485s to one BACnet Gateway, connect each BUS-A/BUS-B of
other PI485s to be connected to BUS-A/BUS-B of the PI485.
2. Connect the BUS-A of the PI485 to the TX of the BACnet Gateway and the BUS-B to the RX.
• Connect LG-NET 1~4 to any of the BACnet Gateway. (Connect the LG-NET to the RS-485 port)
• 64 outdoor units at maximum can be connected to each 485 port of the BACnet Gateway and the
number of indoor units to be connected to the BACnet Gateway is 256 at maximum.
Note: Disconnect the connector from the 485 port of the BACnet Gateway, connect the BUS-A to
the TX and the BUS-B to the RX by using the (-) driver, and then connect the connector to the
485 port of the BACnet Gateway. Because the 485 communication line has a polarity, connect
the line correctly.
1
DI
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
MENU/
17
SELECT
18
19
20
1
DO
2
3
4
BACnet Gateway side
TX
RX
18 BACnet Gateway
1
TX
TX
LG-NET 1
RX
TX
LG-NET 2
RX RX
TX
LG-NET 3
RX
TX
LG-NET 4
RX
TX
Ext 1
Shield line of 0.75 mm
RX
TX
Ext 2
RX
(RS-485 communication line)
ACT
Ethernet 1
LNK
ACT
Ethernet 2
LNK
TX
Console
RX
Run
Power
PI485 side
BUS-A
BUS-B
ON KSDO4H
L1 2 3 4
2
PI485 PI485 PI485
ON KSDO4H
L1 2 3 4
PI485 PI485 PI485
ON KSDO4H
L1 2 3 4
2
PI485
Multi V
Multi V
Multi V