Modbus-Tcp/Rtu - Hitachi EHV+ Series Applications Manual

3.13 Modbus-TCP/RTU

3.13.1 Introduction
Supported function codes are shown in the below table.
16# 10#
0x01 01 Read Coils
0x02 02 Read Discrete Inputs
0x03 03 Read Holding Registers
0x04 04 Read Input Registers
0x05 05 Write Single Coil
0x06 06 Write Single Register
0x0F 15 Write Multiple Coils
0x10 16 Write Multiple Registers
0x17 23 Read/Write Multiple Registers
X = Supported, - = Not supported
Modbus command processing is executed in bus cycle tack, which is configured in PLC settings of Device as below.
You can specify any existing IEC tasks. If the bus cycle task is <unspecified>, task with the shortest cycle time is
taken.
N o t e
If Modbus-RTU or TCP function is needed, be sure to use EHV-CPU1025 or higher model because Modbus libraries
require about 100KB of user program memory.
Function code
Modbus-TCP Master
Modbus-RTU Master
CPU
Modbus-TCP Slave
X
X
X
X
X
X
X
X
X
3 – 32
EH-SIO
Modbus-RTU Master
- X
- X
X X
X X
- X
X X
- X
X X
X X