Communication Specification - Hitachi NES1-004SB Quick Reference Manual

8.1 Communication Specification

NE-S1 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 are in the
following table.
Item
Transmission speed
Communication mode
Character code
LSB placement
Electrical interface
Data bits
Parity
Stop bits
Startup convention
Wait time for response
Connections
Connector
Error check
Cable length
The network diagram below shows a series of inverters communicating with a host computer. Each
inverter must have a unique address, from 1 to 247, 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.
Specifications
4800 / 9600 / 19.2k / 38.4k bps
Asynchronous
Binary
Transmits LSB first
RS-485 differential transceiver
8-bit (Modbus RTU mode)
None / even / odd
1 or 2 bits
One-way start from host device
0 to 1000 msec.
Station address numbers from 1 to 247
Terminal connector
Overrun, Framing block check code,
CRC-16, or horizontal parity
500m maximum
1
8 - 1
Chapter 8 Communication Functions
User-selectable
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