Profibus is the most widely used open fieldbus international standard in the world, divided into FMS, DP and PA
Level 3, DP communication rate can be as high as 12Mb. Profibus is used to connect intelligent devices such as distributed I/0 stations and field bus instruments.
Communication between the process station, operator station and engineering station takes place via the system bus DigiNetS (Industrial Ethernet). user
Different transmission media (RJ45 twisted pair, thin, thick or fiber optic cables and mixed media) and network topology can be selected for the system bus.
Simple layout, due to the use of TCP/IP protocol, the system can also use the public telephone network (dial-up mode) or satellite to achieve ultra-long-distance communication.
Subsystems such as PLC communicate with the Industrial” system through the ModBus protocol interface. The system also supports IEC870-5 over-control protocol.
discussion.
The Flash EPROM inside the PS provides more than 220 functional modules (control algorithm subroutines), in addition to the basic ones specified in the IEC 61131 3 standard
In addition to this content, many powerful and rigorously tested function blocks from actual engineering applications have been expanded. any complex control
The scheme can be realized by the combination of these function blocks.
The function blocks provided by the system mainly include the following categories:
o
Analog processing
o
digital processing
loop regulation
Logical sequence
