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