B–2
Introduction
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.
RS485 serial network
The specifications for SJ300 Series RS485 serial communications are in the following table:
Item
Transmission speed
Communication modes
Synchronization
Character code
LSB placement
Electrical interface
Data bits
Parity
Stop bits
Start convention
Wait time for response
Connections
Error check
SJ300
1
Specifications
2400 / 4800 / 9600 / 19200 bps
Half duplex (one device transmits at a time)
Direct current transmission
ASCII codes
Transmits LSB first
RS485 differential transceiver
7 or 8 bits
None / even / odd
1 or 2 bits
One-way start from host device command
10 to 1000 ms
Station address numbers from 1 to 32
Overrun / Fleming block check code / vertical
or horizontal parity
SJ300
SJ300
2
32
User-selectable
✔
✘
✘
✘
✘
✘
✔
✔
✔
✘
✔
✔
✘