Chapter 4 Parameters
VFD-EL-W 
4-79 
 
(8 , O , 2) 
Start
 bit
bit
12-bits character frame
Stop
bit
parity
 
 
  Communication Protocol 
1. Communication Data Frame 
ASCII mode: 
STX   Start character ‘:’ (3AH)  
Address Hi  Communication address: 
8-bit address consists of two ASCII codes. 
Address Lo 
Function Hi  Command code: 
8-bit command consists of two ASCII codes. 
Function Lo 
DATA (n-1) to DATA 0 
Contents of data: 
Nx8-bit data consists of 2n ASCII codes. 
n ≤ 20, maximum of 40 ASCII codes. 
LRC CHK Hi  LRC checksum: 
8-bit checksum consists of two ASCII codes. 
LRC CHK Lo 
END Hi  End characters: 
END1 = CR (0DH), END0 = LF (0AH) 
END Lo 
 
RTU mode: 
START  A silent interval of more than 10 ms 
Address  Communication address: 8-bit address 
Function  Command code: 8-bit command 
DATA (n-1)  
to  
DATA 0 
Contents of data: 
n×8-bit data, n ≤ 40 (20 x 16-bit data). 
CRC CHK Low 
CRC checksum: 
16-bit checksum consists of two 8-bit characters. 
CRC CHK High 
END  A silent interval of more than 10 ms 
 
2. Address (Communication Address) 
Valid communication addresses are between 0–254. A communication address of 0 means broadcast to all 
AC motor drives (AMD). In this case, the AMD broadcast does not reply with any message to the master 
device.  
00H: broadcast to all AC motor drives 
01H: AC motor drive with address 01 
0FH: AC motor drive with address 15 
10H: AC motor drive with address 16 
   : 
FEH: AC motor drive with address 254 
For example, send communication to AMD with address 16 decimal (10H): 
ASCII mode: Address = ’1’,’0’ => ‘1’ = 31H, ‘0’ = 30H 
RTU mode: Address = 10H