Hitachi SJ300 Series Item, Specifications, User-selectable

B–2

Introduction

Introduction

Appendix B

SJ300 inverters have a built-in RS485 serial communications interface. This serial communications function provides a way of controlling from 1 to 32 inverters on a common serial network. In a typical application, a host computer or controller is the master and each of the inverter(s) is a slave, as shown in the figure below.

SJ300 SJ300 SJ300

1 2 32

RS485 serial network

The specifications for SJ300 Series RS485 serial communications are in the following table:

Item	Specifications	User-selectable
Transmission speed	2400 / 4800 / 9600 / 19200 bps	✔
Communication modes	Half duplex (one device transmits at a time)	✘
Synchronization	Direct current transmission	✘
Character code	ASCII codes	✘
LSB placement	Transmits LSB first	✘
Electrical interface	RS485 differential transceiver	✘
Data bits	7 or 8 bits	✔
Parity	None / even / odd	✔
Stop bits	1 or 2 bits	✔
Start convention	One-way start from host device command	✘
Wait time for response	10 to 1000 ms	✔
Connections	Station address numbers from 1 to 32	✔
Error check	Overrun / Fleming block check code / vertical	✘
	or horizontal parity