211 
occupies one byte 
“Start address” means reading data form the address and it occupies 2 bytes with the fact 
that the high bit is in the front and the low bit is in the behind.   
“Data number” means the reading data number with the unit of word. If the “start address’ is 
0004H and the “data number” is 0002H, the data of 0004H and 0005H will be read.   
CRC occupies 2 bytes with the  fact that the high bit is in the front  and the low bit is in the 
behind. 
RTU slave response message (from the inverter to the master) 
START  T1-T2-T3-T4 (transmission time of 3.5 bytes)
ADDR  01H 
CMD  03H 
Byte number  04H 
Data high bit of address 0004H  13H 
Data low bit of address 0004H  88H 
Data high bit of address 0005H  00H 
Data low bit of address 0005H  00H 
CRC CHK low bit  7EH 
CRC CHK high bit  9DH 
END  T1-T2-T3-T4 (transmission time of 3.5 bytes)
The meaning of the response is that:   
ADDR = 01H means the command message is sent to the inverter with the address of 01H 
and ADDR occupies one byte 
CMD=03H means the message is receiced from the inverter to the master for the response 
of reading command and CMD occupies one byte 
“Byte  number”  means  all  byte  number  from  the  byte(excluding  the  byte)  to  CRC 
byte(excluding the byte). 04 means there are 4 byte of data from the “byte number” to “CRC 
CHK  low  bit”,  which  are  “digital  address  0004H  high  bit”,  “digital  address  0004H  low  bit”, 
“digital address 0005H high bit” and “digital address 0005H low bit”. 
There are 2 bytes stored in one data with the fact that the high bit is in the front and the low 
bit is in the behind of the message, the data of data address 0004H is 1388H,and the data of 
data address 0005H is 0000H. 
CRC occupies 2 bytes with the fact that the high bit is in the front and the low bit is in the 
behind.