Endian Function - Omron MX2 Series User Manual

8-7-5

Endian Function

In communications, endian refers to the byte order in single-word communications data to be
sent/received.
Generally, big endian (where the MSB-side byte is stored first) and little endian (where the LSB-side
byte is stored first) are used.
Special endian is a kind of big endian where the word order of double-word data is reversed. For
3G3MX2-EV2 Series Inverter, Modbus communication is configured in big endian.
The endian function can set endian only for data sent/received in communications (without changing
the address).
In the Modbus Mapping Endian Selection (P400), set the endian you want to use.
The Modbus Mapping Endian Selection (P400) setting is enabled independent of the Modbus Mapping
Function Selection (P200) setting.
Parameter No.
P400
⚫ Byte order of single-word data
• Relationship between single-word data bits and bytes
Bit
Byte
• Order of data during Modbus communication
Send/Receive byte
order
1
2
⚫ Byte order of double-word data
• Relationship between double-word data bits and bytes
Bit
Byte
• Order of data during Modbus communication
Send/Receive byte
order
1
2
3
4
Multi-function Compact Inverter 3G3MX2-EV2 User's Manual (I666-E1)
Function name
Modbus Mapping Endian
Selection
8 to 15
MSB byte
Big endian
MSB byte
LSB byte
24 to 31
MSB byte
Big endian
MSB byte
Data 1
Data 2
LSB byte
8 Communications Functions
Data
00: Big endian
01: Little endian
02: Special endian
7 to 0
LSB byte
Little endian
LSB byte
MSB byte
16 to 23
Data 1
Little endian
LSB byte
Data 2
Data 1
MSB byte
Default data
00
Special endian
MSB byte
LSB byte
8 to 15 7 to 0
Data 2 LSB byte
Special endian
Data 2
LSB byte
MSB byte
Data 1
Unit
−
8
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