Introduction

I Main Function Instruction of the System

l Production process flow chart

l Process real-time dynamic picture

l Process parameters monitor

l Process parameters adjust

l Equipment start-stop status display

l Equipment start-stop sequence control, interlock control

l PID control loops

l Process parameters dynamic trend

l Alarm and event records

l Production report (Daily Report) print

2 System Features

System is consist of operator station and engineer station located in the central control room. Local station take charge of local I/O signal acquisition, loop control, interlocking sequence control, and all local signals are led to local station via cables. Central station is in charge of monitoring equipment operation status, processing and printing production information, sending commands of system start or stop, adjusting loop, setting the values etc. Information and data exchange between each local station and operator station is carried out via industrial local bus, which reflects the principle of “decentralized control, centralized management”.

(1) System advantage & reliability

 Main equipments integrated by the system are international brand-name products of mature technology which are in line with international standards, and have many successful application in domestic and overseas industries. Local station adopts S7-400 PLC system of SIEMENS COMPANY. Central station adopts DELL computer (Optiplex Series), and is equipped with 24” color display.

(2) System compatibility & scalability

Establishment of the system follows the principle of openness. Its structured system has full  compatibility and scalability for future development. Standard Ethernet structure has good scalability and openness, means that any equipment according with Ethernet protocol can be online, which greatly facilities plug production scheduling management system (MIS system). If expanding a similar production lines, cost will increase by 70% only. If converting the production scale into bigger one, the present system can be transplanted for using without additional costs.

(3) System simplicity & economy 

The DCS system uses SIEMENS PCS7-400 system of better cost-performance. This system is of high reliability and less maintenance, and modular structure, easy to replace, and does continuity of production will not be affected.

(4)  Application software features

Software applied in this system can meet requirements of control process production and ensure reliable and safe operation of the production line; at the same time, improve the operation rate of equipment.  The mature programming technique adopted by the system according to requirement of production process control make sure that all hardware resources of this system can be fully utilized.

Good interface of this system has following unique features except for normal functions of common DCS system.

l System interface has English language including various display screens, alarms, records and production records etc., as well as hint and help.

l It can be operated fully by mouse, separated from keyboard, which is simple, convenient and easy to learn.

l The query function of equipment list can view the files and operation condition of any equipment at any time.

l Strict management function

l Fault and problems are easy to identify and distinguish responsibility. DCS system has a detailed record of occurred faults and operation process of each equipment. The record can not be revised, and has four-class permission password protection.

l This system is easy to be connected with production scheduling management system (MIS system). It provides a lot of the necessary data for the MIS system for decision-making of senior management.

Economy of the system is derived from its high cost performance. Recently along with development of computer technology, control ability of PLC system greatly improved. Fully use of its hardware and software resources increase the cost performance.

3 System function

(1) The system can completely monitor the complete system monitor, manage and control the main production process of the entire production line.

(2) In the central control room, operators can monitor the production process, real-time dynamic parameter of each measuring point, status and important parameter of each equipment. The system displays the total appearance chart, operation panel, real-time trends, historical trends and real-time operating functions etc.

(3) The system can provide a number of alarm processing functions, and keep the alarm information for long time. Alarm messages can indicate detailed process including when an alarm occurs, for what reason, when processing is carried out and completed etc., and then record them in order; it can automatically print the record or print them under print command at any time.

(4) System software has equipment self-diagnosis function for central operation station, engineer station, network bus, ancillary equipment and all I/O cards. The operation stations are mutual hot standby to each other; the engineer station can be used as operation station. Either central station failure, any equipment or module failure in the system will not affect normal operation of the entire system.

(5) Operator station is mainly responsible for production monitoring, production information management, alarm information processing, recording, printing. Local station mainly complete the I/O data acquisition, loop control, sequence interlock control, collection of necessary date to monitor and manage.

(6) The data communication network of the system is an open bus Ethernet, whose communication speed is 100MB, adopting redundant network. It is of high communication speed, high reliability, and easy to expand. These features make it conveniently collect automatic control system date without affecting its normal operation.

(7) During running process of the system, database can be maintained on line (password authorization), and program and program modifying  can be made on line without affecting functions of the system.

(8) The system can automatically control the adjust loop.

(9) Each control of the system has condition checking, with error prevention measures on both hardware and software. It can automatically check the input and output parameter range and prohibit the output of parameter exceeding the range. It also has 4-class password protection function to prevent abnormal operation and misuse.