Modbus-Tcp/Rtu; Introduction - Hitachi MICRO-EHV+ Applications Manual

Chapter 3 Programming

3.15 Modbus-TCP/RTU

3.15.1 Introduction

Supported function codes are shown in the below table.
16# 10#
0x01 01
0x02 02
0x03 03
0x04 04
0x05 05
0x06 06
0x0F 15
0x10 16
0x17 23
X = Supported, - = Not supported
Modbus command processing is executed in bus cycle task, 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
When using Modbus-TCP slave or Modbus-RTU slave, be sure to send correct messages from master according to
the Modbus specifications, otherwise slave could fail to respond correctly.
Function code
Read Coils
Read Discrete Inputs
Read Holding Registers
Read Input Registers
Write Single Coil
Write Single Register
Write Multiple Coils
Write Multiple Registers
Read/Write Multiple Registers
Modbus-RTU Master
Modbus-TCP Master
X
X
X
X
X
X
X
X
X
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Modbus-RTU Slave
Modbus-TCP Slave
-
-
X
X
-
X
-
X
X