Gree GMV-V72W/A-F Owner's Manual page 40

(5) For modular outdoor units, if there are multiple outdoor modules, then indoor units must be connected with the last
slave module of ODU (slave module is set by S7 of the outdoor main board).
(6) For modular outdoor units, if there are multiple outdoor modules, the communication matched resistance (installed
before factory) of slave modules connecting with D1/D2 must be removed.
(7) For modular outdoor units, if there are multiple outdoor modules, S7 dip switch of master unit is "00", and S7 dip
switch of slave unit is "10", otherwise, the system main board will display CJ which means address DIP switch code of
system is shocking.
(8) For multi-refrigeration systems, when it is necessary to connect with a centralized controller, the communication lines
connecting with all the ODUs G1/G2 must be connected in series, and the last refrigeration system master unit G1/G2
must be connected with the communication matched resistance (supplied in the list of ODU spare parts).
(9) For multi-refrigeration systems, the address dip switch S3 of the master unit must be set by different numbers
according to Ultra Heat technical service manual, and slave unit S3 can't be set.
4.8.2 Communication connection between IDU and wired controller
There are 4 kinds of connection between IDU and wired controller, as shown below:
Fig.43 One wired controller controls one IDU
Fig.45 One wired controller controls multiple IDUs
Fig.44 Two wired controller controls one
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Ultra Heat GMV Multi VRF