LG PQNFB17C1 Installation & Owner's Manual page 29

Information: Connecting RS-485 of the ACP BACnet
Up to 16 outdoor units can be connected to one RS-485 port of the ACP BACnet, and up to 256
indoor units can be connected to one ACP BACnet. If there are many outdoor units to connect, the
outdoor unit connections shall be appropriately connected to CH1 to CH4 in BUS format. Otherwise,
the ACP BACnet may malfunction.
The following is an example of dividing to CH1 and CH2 and connecting in BUS format.
ACP BACnet
The next shows the wrong example (STAR connection) of RS-485 connection of the ACP BACnet.
Caution
If a different type of connection is made other than BUS format as in the figure, the product may
malfunction. So be careful during the installation.
PQNFB17C0
PQNFB17C0
LON N/A SVC
ACP BACnet
BUS-B
BUS-A
BUS-B
BUS-A
BUS-B
BUS-A
INSTALLING ACP BACnet
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