GREE                                                                        GMV5E DC INVERTER VRF UNITS SERVICE MANUAL 
    67   
7.3.2 Connection of Communication Cables 
The communication bus of indoor and ODUs must be connected in series instead of in star mode. 
The last IDU of the bus shall be connected to a matching resistor (placed in the package of the ODU). 
 
 
 
7.3.3 Communication Cable Connection Method and Procedure 
Communication cable connection between the IDUs and ODUs 
The communication cable between the IDUs and ODUs is connected via interface D1/D2 on the 
terminal  block  XT2.  Connection  modes  for  the  single-module  system  and  multi-module  system  are 
shown in the following figures. 
 
Communication cable connection for the single-module system