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Specifications Section 1-6
Modbus-RTU Specifications
Note Modbus-ASCII mode is not supported.
Supported Commands
Item Description
Mode Modbus-RTU slave mode (See note.)
Baud rate 1,200/2,400/4,800/9,600/19,200/38,400/57,600/115,200 bps
Default: 19,200 bps
Data length 8 bits
Parity Odd, even, or none
Default: Even
Stop bits Odd or even parity:1 bit
No parity: 2 bits
Address setting
range
1 to 247 (broadcasting: 0)
Frame format Slave address: 1 byte
Function code: 1 byte
Data: 0 to 252 bytes
CRC code: 2 bytes
Function code
(hexadecimal)
Function Modbus name
01 Reads multiple bits from the CIO, Work,
Holding, or Auxiliary Area of I/O memory.
Read Coils
02 Reads multiple bits from the CIO Area of
I/O memory.
Read Discrete Inputs
03 Reads multiple words from the DM or EM
Area of I/O memory.
Read Holding Registers
04 Reads multiple words from the CIO,
Work, Holding, or Auxiliary Area of I/O
memory.
Read Input Registers
05 Writes a bit in I/O memory. Write Single Coil
06 Writes a word in the DM or EM Area of
I/O memory.
Write Single Register
08 Executes an echoback test. Diagnostic
0F Writes multiple bits in I/O memory. Write Multiple Coils
10 Writes multiple words in the DM or EM
Area of I/O memory.
Write Multiple Registers