LiteOn EVO 6800 Series - Message Format; Message Content; Message Configuration

235
Command
Selection 2
switch is set to OFF
0∶ Keypad
1∶ Control Circuit Terminal (Analog Input)
2∶ Terminal Up/Down
3∶ Modbus Communication
4∶ Pulse Train Input (Including PWM signal input)
Min.: 0
Max.: 4
b1-08
Run
Command
Selection 2
Enabled while E1-00 to E1-07 is set to 4 and the DIP
switch is set to OFF
0∶ Keypad
1∶ Control Circuit Terminal (Sequence Control Input)
2∶ Modbus Communication
Default∶ 0
Range: 0, 1, 2
11.5 Message Format
11.5.1 Message Content
In Modbus communications, the master gives commands to the slave, and the slave responds.
The following table shows the configured message for both sending and receiving, and the
length of data packets is determined by the command (function) content.
11.5.2 Message Configuration
ASCII scheme:
STX
Start = ‘: ’ (3AH)
Address Hi
Station address:
8-bit, consists of two ASCll codes
Address Lo
Function Hi
Function code:
8-bit, consists of two ASCll codes
Function Lo
DATA (n-1)
Data Characters:
n×8-bit, consists of two ASCll codes
n<=16, max. 32 ASCII codes (20 pieces of data)
…….
DATA 0
LRC CHK Hi
LRC check code:
8-bit, consists of two ASCll codes
LRC CHK Lo
END Hi
End:
END Hi = CR (0DH), END Lo = LF(0AH)
END Lo
RTU scheme:
START
Duration of input singal time is greater than equal 10ms
Address
Station address: 8-bit binary
Function
Function code: 8-bit binary
DATA (n-1)
Data Characters:
n×8-bit data, n<=16
…….