Goodrive300-LIFT series inverter    Communication protocol 
-116- 
Figure 10-5 is the star connection. Terminal resistor should be connected to the two devices which 
have the longest distance. (1# and 15#device) 
1#
15#
32#
6
#
Main 
control 
device
 
Figure 10-5 Star connection 
It is recommended to use shield cables in multiple connection. The basic parameter of the devices, 
such as baud rate and digital check bit in RS485 should be the same and there should be no repeated 
address. 
10.3.2 RTU mode 
10.3.2.1 RTU communication frame format 
If  the  controller  is  set  to  communicate  by  RTU  mode  in  Modbus  network  every  8-bit  byte  in  the 
message includes two 4-bit hex characters. Compared with ACSII mode, this mode can send more 
data at the same baud rate. 
Code system   
1    start bit 
7  or  8  digital  bit,  the  minimum  valid  bit  can  be  sent  firstly.  Every  8  bit  frame  includes  two  hex 
characters (0...9, A...F)   
1    even/odd check bit . If there is no checkout, the even/odd check bit is inexistent. 
1    end bit (with checkout), 2 Bit(no checkout) 
Error detection field 
CRC 
The data format is illustrated as below: 
11-bit character frame (BIT1–BIT8 are the data bits) 
10-bit character frame (BIT1–BIT7 are the data bits)