Fieldbus control system is a hot spot of automation technology at present, and it is paid more and more attention by domestic and foreign automation equipment manufacturers and users.
The appearance of fieldbus control system will bring another revolution in process control system in the field of automation, and its depth and breadth will exceed any period in history, thus creating a new era of automation.
(1)FCS is the fifth generation process control system and the development direction of automation control system in the 20th century. It is the integration of 3C technology (communication, computer and control). The basic tasks are: essential safety, dangerous areas, variable processes, difficulties and abnormal environment.
(2) Fully digital, intelligent and multifunctional, replacing instruments, meters and control devices that simulate a single function.
(3) Use two wires to connect scattered field instruments and control devices, instead of using two wires for each instrument. "Field control" replaces "decentralized control"; Data transmission adopts "bus" mode.
(4) The bidirectional digital communication bus from the control room to the field equipment is an interconnected, bidirectional, serial multi-node and open digital communication system, rather than a unidirectional, single-point, parallel and closed analog system.
(5) Replace centralized control station with decentralized virtual control station.
(6) Transfer the microcomputer processor to the on-site automatic control equipment, so that the equipment has digital calculation and digital communication capabilities, high signal transmission accuracy and long transmission distance. Realize digital signal transmission, decentralized control functions and unified and open standards.
Extended data:
FCS has (1) good openness, interoperability and interchangeability. (2) Full digital communication. (3) Intelligentization and functional autonomy. (4) Highly dispersed. (5) strong applicability.
Functional constituencies have three main points:
The core of (1)FCS system is bus protocol, that is, bus standard.
Using twisted pair, optical cable or radio to transmit digital signals reduces a large number of wires and improves reliability and anti-interference ability.
FCS is always a digital signal from sensor, transmitter to regulator, which makes it easy for us to deal with more complex and accurate signals. The error code function of digital communication can detect the error code in transmission.
FCS can completely disperse PID control to field devices.
FCS based on fieldbus is a fully distributed, fully digital, fully open and interoperable new generation production process automation system, which will replace one-to-one 4 ~ 20 mA analog signal lines and bring revolutionary changes to the traditional industrial automation control system architecture.
According to the definition of IEC6 1 158, Fieldbus is a digital, two-way transmission and multi-branch communication network between the field equipment installed in the manufacturing or process area and the automatic control equipment in the control room.
Fieldbus enables the measurement and control equipment to have digital calculation and digital communication capabilities, improves the accuracy of signal measurement, transmission and control, and improves the functions and performance of the system and equipment.
The SC65C/WG6 working group of IEC/TC65 started from 1984, and went through a difficult course of 16 years. Then, IEC6 1 158-2 was launched in 1993, and then the standard was formulated.
The international standard IEC6 1 158, which was released in early 2000, has eight subsets, namely:
(1)/KOOC-0/IEC technical report (FFH/KOOC-0/); ② Type 2 control network (supported by Rockwell Company, USA); ③3 Fieldbus (supported by Siemens, Germany).
④4 P-NET (supported by Danish Process Data Company); ⑤5 FFHSE (formerly FFH2) high-speed Ethernet (supported by Fisher Rosemount, USA).
6 Swift-Net (supported by Boeing Company of America); ⑦ Model 7 WorldFIP (supported by Alstom France); ⑧ Type 8 Interbus (supported by American Phoenix Contact Company).
In addition to the eight field buses of IEC6 1 158, IEC TC 17B has adopted three bus standards: SDS (Intelligent Distributed System); ASI (actuator sensor interface); Equipment network.
In addition, ISO published the ISO 1 1898 CAN standard. Among them, Device NET was approved as a national standard by China on October 8, 2002/KLOC-0, and it was implemented on April 6, 2003.
Therefore, it is almost impossible to realize the compatibility and interoperability of these bus types at present.
Interoperability of Open Fieldbus Control System For a specific type of Fieldbus, it is open and interoperable as long as it follows the bus protocol of the same type of Fieldbus.
In other words, no matter what manufacturer's products are, they are not the products of Fieldbus Company. As long as the bus protocol of the same type of bus is followed and the products are open and interoperable, a bus network can be formed.
reference data
Baidu encyclopedia -FCS system