Hitachi SJ700D-004L, Instruction Manual

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Chapter 4 Explanation of Functions
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(2) Message format
Command message that master device sends messages to slave device is called “query”, response message that
slave device sends messages to master device is called “response”,
The formats of the query and response frames are described below.
Query Response
Slave address Slave address for confirmation
Function code Function code for confirmation
Query data Response data
Error check code (CRC-16) Error check code (CRC-16)
(i) Slave address (node allocation)
The slave address is a number 1 to 247 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" at the master device is broadcasted to all the connected inverters. In
case of broadcast communication, all slaves recieve the message, but do not respond.
With a broadcast query, the master device can neither read inverter data nor perform a loopback test.
Slave address of Modbus specification are 1 to 247. In addition, master device can send message to specified slave
devices when slave address set 250 to 254. (Slave device do not respond. Writing command 05h, 06h, 0Fh and 10h
are available.)
Slave address Sending destination
250 (FAh) Broadcast communication to slave address 01 to 09.
251 (FBh) Broadcast communication to slave address 10 to 19.
252 (FCh) Broadcast communication to slave address 20 to 29.
253 (FDh) Broadcast communication to slave address 30 to 39.
254 (FEh) Broadcast communication to slave address 40 to 247.
(ii) 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
Maximum data count in a
message
01h Reads the coil status. 4 32 coils (in units of bit)
03h Reads registers. 8 16 registers (in units of byte)
05h Writes data to a coil. 2 1 coil (in units of bit)
06h Writes data to a register. 2 1 register (in units of byte)
08h Performs a loopback test. -
0Fh Writes data to multiple coils. 4 32 coils (in units of bit)
10h Writes data to multiple registers. 8 16 registers (in units of byte)
17h
Writes/Read data to multiple
registers.
32/32 16 registers (in units of byte)
(iii) Data
The data contains a functional instruction.
The sending format is different depending on the function code.
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