control
All schemes can be realized by the combination of these function blocks.
The function blocks provided by the system mainly fall into the following categories:
o
Analog quantity processing
o
Digital quantity processing
Loop adjustment
Logical sequence control
c
Logical operation
Monitoring function
Acquisition function
c
Arithmetic operation
c
Tcp/ip protocol communication interface
Modbus protocol communication interface
1ec870-5 protocol communication interface (telecontrol)
4.2 field controller PS
Industrial ial “field controller PS is a special process control station, which is embedded with a fieldbus communication interface for users to use
Fieldbus technology provides a very flexible choice. Each PS is allowed to insert 4 fieldbus interface cards (card types can be different),
Each card is connected to a fieldbus to collect process data and