Hitachi SJ700-2 Function code Maximum number of data, Reads the coil status, Reads registers

Chapter 4 Explanation of Functions

The formats of the query and response frames are described below.

Message configuration: Query

Header (silent interval)

Slave address

Function code

Data

Error check code

Trailer (silent interval)

(i)Slave address

The slave address is a number 1 to 32 that is assigned to the inverter (slave) beforehand. (A query is received by the inverter having the same slave address as that specified in the query.)

The query with the slave address set to "0" is broadcasted to all the connected inverters.

With a broadcast query, the master system can neither read inverter data nor perform a loopback test.

(ii)Data

The data contains a functional instruction.

The SJ700 series inverter supports the following Modbus data format:

Data name	Description
Coil data	1-bit binary data that can be referenced and changed
Register data	16-bit data that can be referenced and changed

(iii)Function code

The function code specifies the function to be executed by the inverter.

The table below lists the function codes supported by the SJ700 series inverter.

Function codes

Function code	Function	Maximum number of data
		bytes in a message
01h	Reads the coil status.	4
03h	Reads registers.	8
05h	Writes data to a coil.	2
06h	Writes data to a register.	2
08h	Performs a loopback test.	-
0Fh	Writes data to multiple coils.	4
10h	Writes data to multiple registers.	8

Maximum data count in a

message

32 coils (in units of bit)

4 registers (in units of byte)

1 coil (in units of bit)

1 register (in units of byte)

32 coils (in units of bit)

4 registers (in units of byte)

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