7-9    
ASCII Mode  Framing 
Symbol  Name  Description 
STX  Comm. start  3AH, Char ’:‘ 
ADR Slave address 
Include 2 ASCII code within 1-byte 
Comm. add : 1 ~ 254 convert to Hex representation ; 
Ex. Servo drive ADR is No.20 convert to 14H ; 
ADR = ’1‘ , ‘4’ → ’1‘ = 31H , ‘4’ = 34H 
Function Code  Function code 
Include 2 ASCII code within 1-byte 
Function codes : 03H : Read the register contents, 
06H : Write Single Register , 08H : Diagnostic function, 
10H : Write Multipile Registers 
DATA(n-1) 
│ 
DATA(0) 
Data 
n-word = 2n-byte (ASCII numbers : 4n ), n≦30 
The format of data is depend on Function code 
LRC  Check code  Include 2 ASCII code within 1-byte 
END 1  END 1 (CR) 
0DH;Char ’ \ r ‘ 
END 0  END 0 (LF) 
0AH;Char ’ \ n ‘ 
 
RTU Mode 
Symbol  Name  Description 
STX  Comm. start  Excess comm. loss time setting 10ms 
ADR Slave address 
1-byte 
Comm. address : 1 ~ 254,convert to Hex representation ; 
Ex. Comm. address = 20 convert representation to 14 Hex, ADR 
= ’14H’ 
Function Code  Function code 
1-byte 
Function codes : 03H : Read the register contents, 
06H : Write Single Register , 08H:Diagnostic function, 
10H : Write Multipile Registers 
DATA(n-1) 
│ 
DATA(0) 
Data 
n-word = 2n-byte;n≦30 
The format of data is depend on Function code 
CRC-Low 
Checking 
code-LO 
1-byte 
CRC-High Checking code-HI 1-byte 
END 0  End 0  Excess comm. loss time setting 10ms