Hitachi SJ300 Series Power Supply User Manual


 
Introduction
Appendix B
B–2
Introduction
SJ300 inverters have a built-in RS485 serial communications interface. This serial communica-
tions 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.
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
SJ300 SJ300SJ300
RS485 serial network
12 32