150
3.2 MODBUS communication interface
Modbus realizes communication through RS485 interface, that is, through 485 + / 485 - link on the control panel.
3.3 MODBUS function and information format
Modbus's main function is to read (read) and modify (write) parameters. Different function instructions determine
different operation requests. The MODBUS function of HV610 is shown in the following table:
Functional instruction
Function name
Broadcasting Maximum value of N
0x03
Reading N register words
No
16
0x06
Modify a register ( power down save )
Yes
1
0x05
Modify a register ( power down does not save )
Yes
1
Different function commands determine different Modbus information formats, as follows:
Slave number
0x03
Starting word address
Word number
CRC16
High | low
High | low
Low | high
Function instruction 3 _ host request
Slave number
0x03
Bytes
Starting word value
-
Last word value
CRC16
High | low
High | low
-
High | low
Low | high
Function command 3 _ host response
Slave number
0x06
Starting word address
Data
CRC16
High | low
High | low
Low | high
Function instruction 6 _ host request and slave response (same format)
Slave number
0x05
Starting word address
Data
CRC16
High | low
High | low
Low | high
Function instruction 5 _ host request and slave response (same format)
