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Introduction, Introduction b–2 – Hitachi SJ200 Series User Manual

Page 216

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Introduction

Appendix B

B–2

Introduction

SJ200 Series inverters have built-in RS-485 serial communications, featuring the
ModBus RTU protocol. The inverters can connect directly to existing factory networks
or work with new networked applications, without any extra interface equipment. The
specifications for SJ200 serial communications are in the following table.

The network diagram below shows a series of inverters communicating with a host
computer. each inverter must have a unique address, from 1 to 32, on the network. In a
typical application, a host computer or controller is the master and each of the inverter(s)
or other devices is a slave.

Item

Specifications

User-selectable

Transmission speed

4800 / 9600 / 19200 bps

Communication mode

Asynchronous

Character code

Binary

LSB placement

Transmits LSB first

Electrical interface

RS-485 differential transceiver

Data bits

8-bit (ModBus RTU mode)

(ASCII mode not

available)

Parity

None / even / odd

Stop bits

1 or 2 bits

Startup convention

One-way start from host device

Wait time for response

0 to 1000 msec.

Connections

Station address numbers from 1 to 32

Connector

RJ45 modular jack

Error check

Overrun, Fleming block check code,
CRC-16, or horizontal parity

SJ200

SJ200

SJ200

1

ModBus Network

2

32

Host computer