Supervisory Control & Data Acquisition - Communication Technology Modbus Protocol

An open data communication protocol developed in 1979
Published by Modicon
Open structure
Flexible
Widely known
Supplied by many SCADA and HMI software
Have OPC Servers
2 serial transmission modes:
ASCII 10 bits
RTU (Binary) 11 bits
Communication interface
RS-232/485
Ethernet (TCP/IP)
Station Device: 0 ~ 255
Digital input
1xxxx: 4 digits for hexadecimal address (0000 ~ FFFF)
1xxxxx: 5 digital for decimal address (0 ~ 65535)
Digital output
0xxxx: 4 digits for hexadecimal address (0000 ~ FFFF)
0xxxxx: 5 digital for decimal address (0 ~ 65535)
Analog input
4xxxx: 4 digits for hexadecimal address (0000 ~ FFFF)
4xxxxx: 5 digital for decimal address (0 ~ 65535)
Analog output
3xxxx: 4 digits for hexadecimal address (0000 ~ FFFF)
3xxxxx: 5 digital for decimal address (0 ~ 65535)

Từ khóa: Supervisory Control, Data Acquisition, Communication, Technology, Modbus , Protocol