U-Match Series DC Inverter Service Manual 
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②.
  The  current  consumption  of  module  can  not  exceed  the  current  capacity  provided  by  this 
interface. 
7.2.3 MODBUS interface 
The indoor unit of this series has MODBUS interface. If the user needs to connect the unit to the 
management system of the building, please enquire Gree for the MODBUS protocol.     
 
Figure 2-7-9 
(1) Interface instruction: 
1)  The printing is COM-BMS1 and the interface type is B4B-XH-K3;       
2)  Electrical characteristic: baud rate: 9600bps; standard: RS485; 
3)  Working principle: 
4)  The indoor mainboard can send out the unit operation state through this interface and receive 
logical control information to realize control and monitor of the unit. 
(2) Function instructions: 
In order to achieve this function, set the address mode and address through wired controller. Please 
refer  to  Point  3  for  the  setting  method.  You  must  set  the  address  mode  into  long-distance  control 
address mode.   
The address mode is defaulted to be connecting to centralized controller mode and the defaulted 
address is 1. 
(3) Setting method: 
1)  Firstly, set the address mode of wired controller into centralized controller address mode. The 
setting method is: 
Under off state of the unit, press Function and Timer buttons at the same time for 5s to go to the 
debugging  menu.  Press  Mode  button  to  adjust  to  “10”  in  temperature  displaying  zone.  Timer  zone 
displays setting state and press ▲ or ▼ button to adjust. There are 2 selections: 
①.
  Centralized controller address mode (LCD displays 00) 
②.
  Long-distance control address mode (LCD displays 01) 
Choose the second selection and then press Enter/Cancel button to save and exit setting. Now, the