Introduction

The introduction of main system functions:

Main Function Instruction of the System

l  Real-time flow chart picture of the process

l  Real-time dynamic monitoring

l  Process parameters adjustment

l  Equipment start-stop status display

l  Equipment start-stop sequence and interconnected control,

l  interlock control PID control loops

l  Process parameters dynamic trend chart

l  Alarm and event records

l  Production report (Daily Report) print

  The system consisted of operator station and engineer station located in the central control room. Local station takes 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  Advantages and Reliability of the System

 Main equipment which integrates into the system are the products with the international criteria ,

Which is of advanced technology and owns a great number of used cases in domestic and overseas. Local station adopts S7-400 PLC system of SIEMENS COMPANY and  Central station adopts DELL computer (Optiplex Series) equipping with 24” color display.

2 Compatibility and scalability of the System

Establishment of the system adopts the system structure with full compatibility and scalability, which follows the principle of openness.

Standard Ethernet structure has good scalability and openness ,meaning that any equipment in accordance with Ethernet protocol is available to internet, which greatly facilitates the function of plug production scheduling management system (MIS system). If a similar production lines is needed, cost will be less than 70% only. If production line needs to update to larger capacity, the present controlling system can be transplanted to use without any additional fee.

3 Simplicity and cost-efficiency of System

The DCS system utilizes SIEMENS PCS7-400 system which is of high reliability and less maintenance requirements, and it’s easy to repair and replace broken spares because of  the modular structure without impacting the continuity of production.

4.  Application software features

The software applied in this system can meet requirements of production line control and ensure reliable and safe operation for the production line;

It also can strengthen efficiency in operation and make most of it by the mature program techniques according to the controlling demands in production process.

This system is equipped with excellent interface, except some basic functions in DCS and common characteristics and demands , it possesses some unique features as follow:

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 files of each equipment can be viewed due to the inquiry function , which you can search on the surface.

l Strict management function

l  Fault and problems are easy to identify and distinguish respectively. DCS system has a detailed records of occurred faults and operation process of each equipment. The record can not be revised ,and it has the function of 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 in order to get wise decision-making for senior management.

This system is cost-efficient with all the excellent performances above. Recently, along with rapid development of computer technology, PLC system has been greatly improved in terms of hardware and software usages.

3 System function

(1)   The monitoring system can put the management and control of whole production line under surveillance.

(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 functions 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.