Chapter 4 explanation of functions, 4 communication functions – Hitachi SJ700-2 User Manual

Page 179

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Chapter 4 Explanation of Functions

4.4 Communication Functions

The inverter can engage in RS485 communications with an
external control system that is connected to the TM2 terminal
block (on the control circuit terminal block board) of the inverter.

A001: Frequency source setting
A002: Run command source setting
C071: Communication speed selection
C072: Node allocation
C073: Communication data length selection
C074: Communication parity selection
C075: Communication stop bit selection
C078: Communication wait time
C079: Communication mode selection

Related code

The SJ700 series inverter shares the ASCII communication
protocol with the SJ300 and L300P series inverters.


(1) Communication specifications

Item

ASCII mode

Modbus-RTU mode

Remarks

Transmission speed

2,400, 4,800, 9,600, or 19,200 bps

Selection with the digital operator

Communication method

Half-duplex communication

Synchronization method

Start-stop transmission

Asynchronous

transmission

Transmission code

ASCII code

Binary code

Transmission method

Transmission beginning with the lowest-order bit

Applicable interface

RS485

Data bit length

7 or 8 bits

8 bits

Selection with the digital operator

Parity

No parity, even parity, or odd parity

Selection with the digital operator

Stop bit length

1 or 2 bits

Selection with the digital operator

Initiation method

Initiation only by a command from the external

control system

Waiting time

10 to 1,000 ms

0 to 1,000 ms

Setting with the digital operator

Connection format

1-to-N connection (N: Maximum of 32 [inverters])

Station number to be selected
with the digital operator

Error check

Overrun, framing, BCC,

vertical parity, and

longitudinal parity errors

Overrun, framing, CRC-

16, and longitudinal

parity errors


<Specifications and connections of RS485 ports>
For the RS485 communication function, use the TM2 terminal block on the control circuit terminal block
board.

Control circuit block

Abbreviated

name of
terminal

Description

SP

Positive signal terminal

for transmission

SN

Negative signal terminal

for transmission

RP

Terminal to enable the

terminating resistor

SN

Terminal to enable the

terminating resistor

Control circuit
block board






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