1. System overview and project background
ABB IndustrialIT system is the latest enterprise automation solution developed on the basis of ABB’s original control system. The system integrates the advantages of traditional DCS and PLC and supports a variety of international fieldbus standards. It is especially suitable for the application of cement industry, which is widely used in the cement industry.
In 2001, Anhui Conch Group set up two 2500 t/d production lines and four 5000 t/d production lines, all using ABB AC800F control system, which has been running well for three years. In 2004, on the basis of this good cooperation, 11 5000 t/d and 10000 t/d production lines were set up on a large scale. All use ABB control systems. In 2005, there will be six more 5000 t/d and 10000 t/d production lines using ABB control systems. This paper focuses on the 2×5000 t/d production line project in Chizhou and introduces the successful application of AC800F system in conch from the technical point of view.
2. DCS control network
The system network is divided into two layers: field control layer and central monitoring layer.
The first layer is the field control layer. ABB S800 remote I/O adopts Profibus DP communication standard to communicate with AC800F controller. The communication rate is as high as 12MB/s and the distance is as far as 1200 meters. Some fieldbus instruments are used in the field, and ProfiBus PA communication standard is adopted to communicate with AC800F controller.

146031-01

146031-01

146031-01

146031-01

146031-01

The second layer is the central monitoring layer, which realizes the communication between each controller and operator station and engineer station. Industrial Ethernet based on TCP/IP protocol is adopted. Due to the characteristics of cement industry, the controller and operator stations are scattered, and the distance is far, so the field interference is large, so the communication network adopts the redundant fiber ring network structure. The hub provides dual redundant power supply and dual optical fiber interface, which can connect the cable into a ring. The communication module has built-in redundancy management function. When a fault occurs at any part of the loop, it can automatically switch to another standby line within 30ms, and the fault location can be detected at the same time.
3. DCS process control station
3.1 Feature description of DCS control station
The process control level includes a number of ControlIT control stations to complete various control functions, ControlIT control station is composed of AC800F field bus controller and S800 distributed intelligent I/O station hanging down. AC800F controller is very powerful, equipped with 150MIPS 32-bit supermax RISC processor (reduced instruction system CPU)Intel80960HT25/75, And equipped with large capacity memory (4M FlashEPROM and 4 ~ 16M RAM) and real-time multi-task embedded operating system pSOS+, fully meet the industrial process control to the real-time and reliability of the strict requirements. The control period of the controller can be set according to the control requirements, the fastest can be set to 5ms. I/O module scanning speed is very high, for analog quantity T<20ms, for switching quantity T<5ms. The controller has the function of self – diagnosis based on Web technology and remote diagnosis through Internet.
Each S800 I/O station configured by the ControlIT control station can support 12 I/O cards, I/O cards using photoelectric isolation technology, analog I/O card accuracy is not less than 0.1%(thermal resistance is 0.05%). The AI card can drive the two-wire 24VDC transmitter within the range of 600m, which can directly supply power to the field transmitter. The DO output is isolated by a relay whose output contact capacity is DC24V/5A. S800 I/O adopts modular design, DIN rail installation, due to the space and environmental requirements are not harsh, S800 I/O is especially suitable for installation in scattered occasions, and almost no requirements for signal processing, so that the field instrument and equipment signals can be directly connected to S800 I/O station. As is known to all, the environment in the cement factory is very bad, but these production lines have been running for 3 years, basically no card damage phenomenon.