Omron SYSMAC CP Series, Руководство пользователя

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14 Serial Communications
14-42
CP2E CPU Unit Software User’s Manual(W614)
14-7 Modbus-RTU Slave Function
Modbus-RTU Slave enables to read and write CP2E data from Modbus-compatible masters, such as
host PLCs or host computers, using serial communications.
The serial communication mode is set to Modbus-RTU Slave.
By setting the Modbus-RTU slave address on the CP2E side, the target slave address, function code
and data from the master devices can be transmited.
*1 The data length is always 8 bits.
*2 The number of stop bits is determined by the parity setting.
When setting with parity (even/odd), 1 bit
When setting without parity, 2 bits
* 3 The address cannot be set to 0. In commands, 0 is used to indicate broadcast commands.
14-7-1 Overview
Specifications
Item Contents
Mode Modbus-RTU Slave
Baud rate 1200, 2400, 4 8 00, 9600, 19200, 38 400, 57600, 115200 bps
Data length
8 bits *
1
Parity Odd, Even, None
Stop bits
1 bit (2 bits only when setting to no parity) *
2
Slave addresse
1 to 247 *
3
Frame format Slave address: 1 byte
Function code: 1 byte
Data: 0 to 252 bytes
CRC code: 2 bytes
CP2E CPU Unit Modbus-RTU master device
Host PLC
Host computer etc.
Slave
address
Function
code
Communication
data
Slave
address
Function
code
Communication
data