LG V-NET AC Smart II Advanced Control Smart Owner's Manual page 26

2. AC Smart II Installation
Information: RS485 connection of AC SMART II
Maximum of 64 indoor units can be connected to one AC SMART II, and when the expansion kit
is installed, maximum of 128 indoor units can be connected. If there are many number of outdoor
units to connect, the outdoor unit must be connected in BUS format. If not, AC SMART II can
malfunction.
<Correct example: RS485 BUS format connection>
<Incorrect example: RS485 STAR format connection>
2-11
AC Smart
The left picture shows the correct and
incorrect example of RS485 communication
connection to of AC SMART II.
The upper picture shows the correct example
of RS485 connection to outdoor unit with AC
SMART II in BUS format.
The bottom picture shows the incorrect
example of RS485 connection to outdoor unit
with AC SMART II in STAR format.