Table of contents
1. Overview 5
1.1 1System Structure and Designation 5
1.2 System Features 11
2. LN2000 System Communication network 14
2.1 General 14
2.2 Real-Time Data Network Communication 14
2.3 CAN Communication 16
3. Process Control Station (LN-PU) 19
3.1 Hardware structure 19
3.2 Main Functions 19
3.3 Operating Status 20
3.4 Features of the Process Control Station 21
4. LN200 Intelligent I/O Module 22
4.1 General 22
4.2 Indicators and wring Terminals 23
4.3 Major Technical Data of the I/O Modules 25
5. LN2000 System Configuration 26
5.1 General 26
5.2 System Management (STARTUP) 26
5.3 Configuration of the System Database (DATABASE) 27
5.4 Configuration of the SAMA Graphic 28
5.5 Configuration of the Monitoring Graphic (GRAPHIC) 29
5.6 Features of the LN2000 Configuration Software 30
6. Monitoring of LN 2000 System Operation 32
6.1 General 32
6.2 Monitoring pictures 32
6.3 Real-time Trend 34
6.4 Real-time Alarm 35
6.5 Self-diagnosis 36
7. Control Algorithm of the LN2000 System 37
7.1 General 37
7.2 Control Algorithm Block of the LN2000 System 37
7.3 Features of LN 2000 Control Algorithm Block 38
8. Storage and Retrieving of Historical Data 39
8.1 General 39
8.2 Storage of Historical Data 39
8.3 Retrieving of Historical Data 40
9. Function Realization of the LN2000 SOE System 46
9.1 General 46
9.2 SOE System Philosophy 46
10. Interfaces with Other Systems 48
10.1 General 48
10.2 OPC General Purpose Interfaces 48
10.3 Other Interfaces 49
11. Hardware Installation of the LN2000 System 50
11.1 General 50
11.2 Dimensions and Installation of the Cabinet 50
11.3 Internal Layout of the Process Control Cabinet 51
11.4 Internal Arrangement of Relay Cabinet 52
11.5 Distribution Scheme 52
11.6 System Grounding Requirement 53
12. Performance Data Sheet of LN2000 System 54
12.1 System Capacity 54
12.2 Network Performance 54
12.3 Real Time Performance 54
12.4 System Reliability 54
12.5 System Load Rate 55
12.6 Accuracy 55
12.7 Noise Immunity 55
12.8 Environment Condition 55
1. Overview
LN2000 system is a newly developed distributed control system (DCS) which is by Shandong Luneng Control Engineering Co., Ltd., which has made the advantages of conventional DCS systems to go a step further and realize several functions as distributed control centralized display, operation, record and management. Varieties of advanced techniques are adopted such as computation, graphic-display, data communication and state-of the art control etc. technologies. The system, with its rational system structure, powerful function, abundant control software, concise operating interfacefully reflecting modern sense, easily workable configuration and maintenance tools and open communication system is capable of integrating, data acquisition, process control and production management is in it, thus meeting the demands for the control and management of different scaled production processes and having wide application fields.
1.1 System Structure and Designation
1.1.1 Integrated System Structure of LN2000
LN2000 system is a DCS system with high accuracy and reliability, modular and intellectualized structure. The system network structure is shown in Figure 1-1. This is a typical configuration of the control systems of two power generating units. Each unit has an independent control system, which can monitor the common system. Under authorization the common system can be controlled from DCS operator station of any unit.
1.1.2 System Hardware
· Station:
According to the definition of communication devices defined by communication system, hardware devices in communication network are called stations, or nodes. In LN2000 system, there exist the following stations: process control station that is also called lower station, and operator station, engineer station, historical data/record station and external data interface station which are called upper stations or HMI stations.
· Process Control Station (LN-PU):
Taking the high performance microprocessor as the core, the station is able to perform process control operation and fulfill such functions as analogue control and logic control by means of I/O modules, which is abbreviated as PU.
· Operator Station (OS):
The operator station, which has such functions as monitoring, operation, event logging, alarm and data communication of site processes, is a GP computer configured with dedicated software for monitoring.
· Engineer Station (ES):
The engineer station equipped with a GP computer and operating system as well as a complete special configuration software is a normal PC used for application software configuration, system commissioning and maintenance of process control.
· External Data Station:
A station used for communication between LN2000 and other systems. The data coming from other systems are called external data.
· Real-Time Data Network:
A software-hardware structure used for system communication, which connects with process control stations, and operator stations forming an integral distributed control system and making it possible to share distributed process data and management data. A redundant operation mode is applied where double networks operate simultaneously, thus the system communication is realized by using a high performance Ethernet exchanger.
· Intelligent I/O Module:
I/O modules are the interfaces between process control stations and production process. The process control station fulfils process control data acquisition & control over the production process via I/O modules. In LN2000 system, the core of an I/O module is a microprocessor, where data detection and data processing are automatically performed without process control stations involved.
· CAN Field Bus:
CAN is the abbreviation of Control Area Network. In LN200 system, the process control station communicates with intelligent I/O modules over the field bus via a CAN protocol. The CAN Field Bus is also called I/O communication bus or network. Double-network redundancy is also adopted.
· Process Control Cabinet:
The redundant process control stations and I/O modules managed and controlled by the stations are installed into a special cabinet, forming an integrated construction which is called process control cabinet or system cabinet.
1.1.3 Main System Software
· System Management (STARTUP.EXE):
It is an ever-running program, responsible for acquisition, classification and storage of real-time data from process station and collecting on/off statuses of master and slave stations and shares them with other programs via the common memory. Other functions such as user management, other program initiation, process station operation and synchronization of system are also provided.
· System Data Base Configuration (DATABASE.EXE):
It has such functions as fulfillment of configuration for process control stations, modules and all data points as well as relative modification and inquiry, and it has functions for online inquiring of current value and status value of data points.
· SAMA Graphic Configuration (SAMA.EXE):
Based on the algorithm block, the program can perform functions of analog (variable) control and logic control of process control station in the system as well as relative modification via the graphic configuration. An online commissioning function is provided as well.
· Graphic Configuration (GRAPHIC.EXE):
The function of this program is to plot monitoring graphic for operator station. Various basic graphical/plotting tools are provided e.g. tools for plotting of straight lines, rectangles, rounded rectangles, ellipses, sectors, polygons, broken lines, words, bitmap and 3D graphics. Dynamic properties can be defined for all graphics. Connection tools for dynamic data points are provided as well, e.g. analog (variable) points, digital (variable) points, bar charts, pointers, real-time curve, XY curve and alarms etc. and at the same time push buttons and hot spot used for human-machine interaction can also be configured.
· Monitoring (OPTVIEW.EXE):
Monitoring graphics plotted by GRAPHIC.EXE are displayed by this program. Production process can be monitored and operated by the operators via color dynamic graphics.
· Trend Curve (TREND.EXE):
There are two kinds of trend curve: real-time trend curve and historical trend curve. The trend curve program is a multi-file program. In each file, there is a trend group which is saved as a separated file. Trend points in real-time trend read data point information from the system database, receive real-time broadcasting data, and display the changing trend of data points. The real-time trend can acquire historical data several minutes ago, and realize bumpless connection with historical trend; the historical trend reads messages of data points from historical database, reads data from files in historical database and displays the changing trend of a selected time range.
Figure 1-1: Network Structure of LN 2000 DCS System
· Alarm (ALARM.EXE):
The alarm function includes the live alarm list and historical alarm queries. The function of the live alarm is capable of indicating the alarm points of real-time data in the alarm bar and send out sound signals. The initialing and terminating time for the query of historical alarms are set, and alarms between the initialing and terminating time are indicated in the alarm bar.
· Self Diagnosis (SELFTEST.EXE):
The self diagnosis application monitors all status of the complete DCS system, including those of the operator stations, engineer stations, process control stations, CAN network, modules and data channels. Adequate information is offered for the user to attain operation status of the DCS system.
· Historical Data Log (HISSTART.EXE):
It is an application software running on the platform of the historical data station. In LN2000 system, it is unnecessary to configure a historical database. All points in the system database are stored in the historical data. New compaction technology is adopted, thus realizing that real-time database equals to historical database and bumpless connection between real-time trend and historical trend displays.
· Event List (EVENTLIST.EXE):
This application software normally running on historical station consists of both operation log and SOE report. The operation logs include all the operation logs of operators. The resolution of the SOE logs is 1ms.
· Report (REPORT.EXE):
The program running on the historical station can generate reports of various parameters, performance indexes and operating situation in production process.
· General purpose Interface (LN_OPC.EXE):
A data service program in accordance with the universal industrial process control standard (OPC DA2.0) is provided, consequently realizing the high-performance data communication between LN2000 DCS and other industrial process control software.
· GPS Time Service (LN_GPS.EXE):
The time messages are received from GPS module via the serial port to provide DCS system standard clock.
· Other Interfaces:
Other interfaces for a third-party application such as MODBUS and CDT are offered by LN2000 distributed control system upon request
1.2 System Features
1.2.1 Features of System Structure
· High speed, reliable and open communication system
Dual-level communication links are adopted in LN2000 system: real-time data network and CAN field bus. Real-time data network realized by per-to-per architecture without any server carries out the communication between real time messages and commands among individual functional nodes (including those of process control stations, operator stations, engineer stations etc.). The network adopting Ethernet Protocol and redundancy with a communication (Baud) rate of 100Mbps satisfies the requirements for a high speed, reliable and open industrial computer control network. A process control station communicates with individual I/O modules via CAN field bus. Redundant configuration is adopted as well. The communication mode between process control stations and I/O modules is Master-Slave type, which makes communication more reliable.
· Mature, simple and friendly configuration software
A mature operating system e.g. Chinese Edition WINDOWS 2000 supports LN2000 system. Devices used for system configuration, commissioning and maintenance are PC-based technical tools, which can be used either online or offline. All kinds of configuration can be performed and various graphics and reports can be created for system database and operator stations. Meanwhile, technical drawings realizing control strategies can be directly acquired by the control algorithm configuration software via the method of CAD reducing the steps from the design of control strategies to engineering realization. The software is available for site commissioning and parameter setting, which greatly shortens the commencement /commissioning period and reduces repetitive actions.
· Abundant and practical process control algorithm
All algorithms in LN2000 system are graphical which makes it easy to configure and realize intact functions.
Complicated control functions can be accomplished on a control drawing including not only fulfillment of control circuits for analogue variable but logic control circuits. Thus the control of complex production processes is simplified.
Control module adopts independently created and scientific automatic sorting algorithm, where the implementation sequences of algorithm blocks are sorted by an intelligent method, conquering the disadvantages of disturbed control sequence due to conventional configuration sequential sorting.
· Low power consumption and high reliability hardware
Utilizing redundant and fault-tolerant techniques, the whole system operation is uninterrupted by any single component failure, thus ensuring the system reliability.
A low power consuming CPU is adopted for the control station without needing any fan for cooling, which greatly extends its service life and improves its stability. Reliable supervisory control in progress level is realized between the redundant control stations.
Low power consuming components are used for intelligent I/O units. Its modular structure package can reduce dust corrosion and overcome the shortcoming of plug-in card. Cold end temperature compensation and linearization are automatically realized inside the (intelligent) thermocouple module. Zero point and gain can be automatically adjusted, avoiding zero drift.
· Convenient for Maintenance
Online modification and downloading are supported in process control station. It is convenient for commissioning and modification of control logics.
A powerful self diagnosis function is provided for each I/O module. There are relative fewer points in an I/O module, which is available for hot-plug.
Each redundant component can be replaced under normal operation without affecting the system.
1.2.2 Features of Technologies Adopted
· Standardized technologies
Several mature standard techniques are utilized as the basis of the complete LN2000 system, which include IEEE802.3 Ethernet communication architecture and protocol, graphic structure and interface in compliance with ISA and standard PC interface and bus etc., making it much easier to be connected with other system and updated.
· New technologies spreading/popularization
LN2000 system effectively incorporates the latest techniques in relation to PC, GUI, control, and network as well as field bus to save project cost and enhance the reliability. Furthermore, the simulation technology is closely combined with foresaid techniques, greatly facilitating simplifying the system design and commissioning. The friendly HMI and excellent process control functions lead LN2000 to the most customer-reliable distributed control system.
2. LN2000 System Communication network
2.1 General
A distributed control system is characterized by its distributed control, centralized management and the architecture utilizing multiprocessors, so that functions and dangers are distributed while the functions of each set of processor are improved.
To achieve more convenient coordination and management of multiprocessors, they have to be connected together through a network. Thanks to the intelligent modules, the communication between modules turns to flexible changing from the original parallel bus communication to serial mode nowadays. It is apparent that the data transmission technique for communication between individual processors and modules is the most important technology supporting a distributed control system.
This system adopts the currently fashionable communication protocol and network architecture forming the communication network. It has two layers of network structure: the upper one is fast Ethernet, i.e. the communication channel between operator stations, engineer stations and process control stations, which is also called real-time data network; the lower one is CAN protocol based field bus network, which is booming rapidly in the field of industrial control/and to be widely used in the near future. It is applicable for the communication link between process control stations and I/O modules.
2.2 Real-Time Data Network Communication
2.2.1 Network Structure
The Ethernet is adopted as the inter-station communications network for the upper layer network of the system. The network is implemented in strict compliance with IEEE802.3 A and TCP/IP protocol with a communication (Baud) Rate of 100Mbps. The CSMA/CD, an access control method, is applied in Ethernet. In case that there are fewer nodes on the net and communication load is low, the response time of the CSMA/CD is much shorter than that of other access control methods. Thus each station has an excellent real-time performance.
The topological structure of the system is a star style where each station is connected to the data exchanger by twisted pair wiring. Because of the long distance from engineer stations & operator stations to the cabinet, these stations are connected with the data exchanger inside of the cabinet by category 5 shielded cables. The star Ethernet structure is characterized by simple interfaces, easy extension for the bus and station, high reliability and convenient for maintenance. The failure of a single drop will not disturb others.
To warrantee the reliable inter-station data transmission, two independent network exchangers are utilized which are connected to the net and both networks are in running simultaneously to keep an uninterrupted inter-station communication.
2.2.2 Techniques adopted in the communication network
Exception reporting technology and information packing technology are adopted to avoid communication blocking, improve communication efficiency and efficiently use every byte transferred.
· Exception Reporting Technology
Exception reporting means that, for a point in the process control station, if no significant change takes place during process control, no report will be created, i.e. no broadcast of such data will be transferred to the net so that the data flow on the net is reduced. In case significant change occurs (the changed value exceeding defined dead band for the analog variable; the status change for the digital variable), the process control station will send out the data via the network. This action will also be performed if a point seldom changes in a long period (exceeding the Max. exception reporting time) to avoid a time-out decision of the upper station.
· Information Packaging Technology
For a digital variable, the status of a point can be denoted by using a bit of a byte. In this way, a byte can denote the status of 8 points, resulting in greatly improving the availability of a network.
2.2.3 IP Address Allocation of LN 2000 System
The real-time communication network of the LN2000 system consists of 2 networks, i.e. A and B which are redundant for each other. The first two sections of the segment basic address of network A and B are identical, however, the number of the third section of B is one greater than that of A. For example, if the segment basic address of A is “202.206.212.”, then that of B will be “202.206.213.”. The segment basic address of A is set by the configuration application of the system database and that of B is automatically decided based on the address of A.
In the following text, assuming that the segment basic address of network A is “202.206.212.” it is easily to known that of B is “202.206.213.”.
· IP of the process control station
The process control stations are 49 in quantity at the most. The last digit of its IP address of a process control station is identical to the number of base station. The last digit of the IP address of a redundant station equals to the base station number plus 50. The IP address allocation of the process control station is shown in Table 2-1.
Table 2-1 IP Address Allocation of the Process Control Station
Process Control Station 1 Base station Net A 202.206.212.1
Net B 202.206.213.1
Redundant station Net A 202.206.212.51
Net B 202.206.213.51
Process Control Station 2 Base station Net A 202.206.212.2
Net B 202.206.213.2
Redundant station Net A 202.206.212.52
Net B 202.206.213.52
…¡¡… Base station
Redundant station
· IP address of the upper station
The upper station mainly refers to the engineer station and the operator station. The LN2000 system is utilizing a per-to-per network structure without server, where the station number and IP address are allocated in a unified manner. Any IP collision is unallowable in all stations. The last digit of an upper station’s IP address equals to the station number plus 100. For example, the address allocation of No.1 engineer station and No.3 operator station is shown in Table 2-2.
Table 2-2 IP Address Allocation Example of the Upper Station
No.1 Engineer Station Net A 202.206.212.101
Net B 202.206.213.101
No.3 Operator Station Net A 202.206.212.103
Net B 202.206.213.103
2.3 CAN Communication
To adapt the trend of the instrument intelligentization, field bus is utilized which reduces the signal cable costs. The Control Area Network (CAN) is adopted as the field bus network. It is a mature and widely used field bus network characterized by the following aspects:
· Maximum transmission distance of 10Km (5Kbps);
· Short frame structure available, 8 active bytes for each frame, with short transmission time, low Interference probability and fast network response;
· Powerful error detection and correction functions with a low error rate and high reliability;
· Low cost communication media (i.e. normal twisted pair).
The communication between the process control station and intelligent I/O module is realized by the CAN protocol based network. The Baud Rate can be configured as per actual transmission distance. A pair of process control station and its related intelligent I/O modules must have the same Baud Rate. The transmission media used for the network is by using shielded twisted pairs coated with rubber sleeve. The address of an intelligent I/O module on the CAN network can be defined by the toggle switches on the modules. The addressing range is 1~63. This network layer has a redundant and bus topological structure with such advantages as easy expansion & high reliability.
3. Process Control Station (LN-PU)
The process control station (LN-PU) is a computer used for receiving the configuration messages downloaded from the engineer station, collecting I/O module data, performing control strategies and controlling production processes via I/O modules.
3.1 Hardware structure
The most important part in the process control cabinet is the process control station which is composed of the system master board, CPU board, dual CAN interfaces card, power supply, housing and indicators, among which CPU main board is configured with an embedded low power consuming CPU, 64MRAM, 32M E-disc (DOM) and dual 100M Ethernet ports. The maximum Baud Rate is 1M bps.
Power Supply: 220VAC, 0.5A.
The appearance of the process control station is shown in Figure 3-1.
Figure 3-1 Appearance of the Process Control Station
3.2 Main Functions
A real-time Multi-tasking operating system is applied in the LN-PU. The application software is embedded special control software, independently developed. Its main tasks are:
· To receive and perform the control strategies downloaded from the engineer station;
· To receive data collected by the I/O modules;
· To send commands and data to the I/O modules;
· To receive commands from the operator station;
· To send real-time data to the upper stations;
· To realize automatic and redundant back-up.
The application software and downloaded control strategies are stored in the E-disc so that no configuration data will loss in case of a power failure. The process control stations are redundantly configured. The redundancy of the real-time data transmission and the stations is achieved by the built-in dual Ethernet ports redundant for each other. The redundant LN-PU in standby status is capable of automatically tracking the LN-PU in operation, which will seamlessly take over the process control tasks in case of a failure occurred on LN-PN in master control status, realizing bumpless transfer of LN-PN.
The two CAN controllers on the LN-PU communicate with intelligent I/O modules in a master-slave mode, which has complete redundancy capability, and perform the management of the I/O modules.
3.3 Operating Status
The process control station is redundant configured. Each station may be in the following status: initial status, master control operation status, partly tracking status, completely tracking status and offline status. The station in master control operation status is called the master station, while the station in tracking status is called the standby station. The status of a station can be clearly displayed by the indicator on the station panel or via the self-diagnosis software on the upper station.
· Initial Status: indicate no configuration file of control strategies in the LN-PU. If there is no configuration file downloaded in the LN-PU, the LN-PU will automatically enter the initial status after a power up and then the configuration file can be downloaded. After that, the LN-PU will enter the master control status if no control station is detected, otherwise it will change to partly tracking status.
· Master Control Operation Status: in this status, the station collects data from I/O modules, implements control strategies and controls the production process via I/O modules as well as sends real-time data to the upper station and back-up data to the tracking station.
· Partly Tracking Status: during a normal operation of the master station, the later initiated station will enter the partly tracking status, i.e. the configuration files of master station are probably not identical to that of the standby station. In this status, online downloading is available.
· Completely Tracking Status: during normal operation of the master station, the later initiated station will enter the partly tracking status. When the configuration files of control strategies have been copied from the master station to the standby station, the standby station will enter the completely tracking status. In this status, online downloading is available. Upon completion of downloading, if the configuration files of control strategies of the master station and the standby station are not entirely identical, the standby station will change over to the partly tracking status. If a changeover is done between the master and standby station, the control strategies online downloaded will be performed.
· Offline Status: refers to the power supply for the LN-PU is not available or power supply failure.
3.4 Features of the Process Control Station
· A low power consuming CPU is adopted for the control station without needing any fan for cooling, greatly extending its service life and improving its stability as well as providing hardware warranty for the system.
· The hardware watchdog is utilized for the process control station realizing the progress level supervisory control and avoiding casual lock-up.
· An independently developed technique is incorporated in the data broadcasting system. The two networks broadcast simultaneously, achieving balance control of data flow and avoiding the network broadcast “storm” effect.
· Back-up of process station is carried out by using two redundant networks, avoiding the disadvantages of a single back-up by a third-party network or by parallel cables.
· The communication between the process control station and I/O modules is realized by using the CAN field bus with redundant arrangement, which enhances the system reliability.
· The process control station can be configured online or offline and downloaded online after configuration. In this way, the system availability is warranted and the time for startup and maintenance is saved so that it is convenient way for site commissioning and installation as well as for the user’s familiarization with the system.
4. LN2000 Intelligent I/O Module
4.1 General
The LN-B series intelligent I/O modules for the field bus are the latest products which are characterized by the following:
· High-performance and low power consuming 16-bit chip microprocessor;
· Fully independent and isolated dual CAN field bus interfaces;
· Two redundant isolated 24 V DC/DC supplies;
· Two-level hardware watchdogs and offline self-recovery;
· Self sustaining output signals in case of system fault or being reset;
· Channel-channel isolation of analog input/output signals;
· Jumper-selected internal/external supply for analog input signals, supporting the two-wire transmitter;
· The Sequence of Events (SOE) module is equipped with three independent CAN interfaces with high accuracy of synchronization
· Between modules, and the SOE resolution is less than 1 millisecond;
· GPS module with dual CAN interface and RS232/485 port providing standard time.
· Modules available for remote installation and Baud Rate adjustable;
· Transmission distance: 3.3km/20kbps, 620m/100kbps, 270m/250kbps, 130m /500 kbps;
· Protection for modules and self-recovery of communication channels, two-level over current protection;
· Independent power and CAN communication terminals isolated from signal terminals;
· Field power cables can be directly connected to hot-plug terminal board without interruption of transfer;
· Four panel indicator lamps (respectively for power supply, operation, CAN-A status and CAN-B status);
· Complete industry-class components are adopted with a operating temperature range of -10¡æ-60¡æ;
· Dimension: 120mm (W) ´ 112mm (H) ´ 48mm (D), with a horizontally-installed metal enclosure.
The software for the LN intelligent modules is fixed in the chip processor with high system stability. The communication mode is the CAN field bus. 63 intelligent modules at the most can be linked to the field bus with CAN2.0A protocol as the communication protocol. The intelligent modules exchanges data with the process control stations in an interval configured by the customer.
4.2 Indicators and wring Terminals
The appearance of the module is shown in Figure 4-1. For more details, please refer to Table 4-1.
Figure 4-1: The appearance of the Module
Table 4-1: Module Indicator and Wiring Terminals
No. Name Description
1 Panel Indicators Four LED indicators on the panel: a single red, a single green and two double-color (red and green) indicators. From left to right, they respectively denote the status of power (PWR), running (RUN), CANA and CANB.
2 Dual-channel 24 VDC Wiring Terminal Dual£«24VDC±10% power supply. A redundant 24VDC power supply is provided for the module.
3 Double CAN Wiring Terminal Two independent CAN bus interfaces with redundancy for data transmission & receiving.
4 Address Identification Indicates the address number of a module in the control cabinet defined by the toggle switches.
5 Terminal Board Wiring is carried out as per the wiring tags (item 6).
6 Terminal Wiring Tag Indicates the definition of individual wiring terminals.
7 Panel Fixation Fixing holes are located on the four corners of a module panel.
8 Auxiliary Plate Fixation The ellipse fixing holes are located around the auxiliary plate for securing the module to the cabinet rail.
5. LN2000 System Configuration
5.1 General
The control functions of a DCS are realized by configuring system via configuration software, which has a series functions of system design, site commissioning and system maintenance. To adapt the diversified and complicated demands of the process control, the configuration software should have innovative design concept and easily-operated functions. Furthermore, a friendly interface will assist the engineer to design a more reasonable and advanced system.
The configuration software runs on the engineer station, where the operating system of WINDOWS 2000 is adopted. There are three major tool software: the configuration software of the system database (DATABASE), the SAMA graphic configuration software (SAMA) and the configuration software of the supervisory control graphics (GRAPHIC).
Functions like configuration, commissioning, maintenance and monitoring required by the system are integrated into the whole system structure, which is characterized by easy mastering and simplified operation.
The configuration procedures of the LN2000 are:
1) System database configuration by using DATABASE;
2) Control strategies configuration by using SAMA;
3) Monitoring pictures configuration by using GRAPHIC.
5.2 System Management (STARTUP)
The application STARTUP is an ever-running program which must firstly be initiated as soon as entering the LN2000 software system. It is used to collect, sort and save the real-time data of the process stations and collect the start/stop statuses of all stations as well as share them with other applications through the common memory. Its functions also include the user management, initiating other programs, operating process stations and system synchronization. The interface of STARTUP is shown in Figure 5-1.
Figure 5-1: Interface of the System Management Software
5.3 Configuration of the System Database (DATABASE)
The configuration software of the LN2000 system database is used to perform the configuration of stations, modules and all data points and to carry out related modification and polling functions including detecting the current and status value of data points online.
The interface is shown in Figure 5-2 with two split views. The left view in tree structure indicates the configuration information of process stations and modules of individual process stations. The right one shows all the information of data points of currently selected location or current polling results.
Figure 5-2: Interface of the System Database Configuration Software
5.4 Configuration of the SAMA Graphic
In the LN2000 system, the control strategies of a process control station including continuous and sequential control are realized by the SAMA Graphic Configuration Software, meaning that depending on the functions required by the user, the control algorithm blocks internally defined are combined as per a certain logical process to form a complete SAMA graphic. After completion of the SAMA graphic configuration, the application will be compiled and down loaded to the process control stations (LN-PU) before it is called.
The SAMA Graphic Configuration Software realizes the visualization of the control algorithm blocks clearly displaying all related input and output characteristics and providing a convenient human-machine interface for creating, editing and compiling the SAMA graphics. The SAMA graphic is configured taking a page of the station as a unit. Supported by the software, the design of control strategies is converted to the organization and plotting process of algorithm blocks. The algorithm blocks are just needed to be selected from the block library, and connected with signal lines in accordance with specified data processing procedures. The interface of the SAMA software is shown in Figure 5-3.
Figure 5-3: Interface of the SAMA Software
5.5 Configuration of the Monitoring Graphic (GRAPHIC)
The GRAPHIC software is used for plotting monitoring pictures of operator stations. Basic plotting tools are provided to create straight lines, rectangles, rounded rectangles, ellipses, sectors, polygons, broken lines, three-dimensional graphics, texts and bitmaps. Dynamic link tools for data points are provided as well, such as those used for analog points, digital points, bar charts, pointers, real-time curves, XY curves and alarms. An operator monitoring graphic can be easily drawn with the mouse. Each graphic element has a dynamic link. Depending on the situation of the dynamically-linked data points, the graphic elements will change color, blink, hide or move. The provided push buttons and hot spot tools simplify the communication between the operator and the system. The push buttons and focuses (poke field) can be defined to switch and pop up windows as well as send operation commands. Abundant editing functions are provided which greatly improve the working efficiency. The interface of the GRAPHIC software is shown in Figure 5-4.
Figure 5-4: Interface of the Monitoring Graphic Configuration Software
5.6 Features of the LN2000 Configuration Software
5.6.1 Shortening Design Period and High Efficiency
The software DATABASE allows the data imported from an EXCEL (Microsoft) table via a template program forming a complete shared system database. The applications DATABASE, SAMA and GRAPHIC run in a visualization mode. The edit functions such as “Copy” and “Paste” will reduce the workload so as to save the engineering time.
5.6.2 Easy Online Modification of parameters and convenient for Commissioning
All control strategies are configured in the DATABASE and SAMA. During system commissioning, the software runs in the online mode, monitoring the real-time data from all data points and modules. If it is required to modify a certain parameter, just open the attribute dialogue box to modify the value, and then click the “YES” button.
5.6.3 Online Downloaded LN-PU Control Strategy, safe & reliable
In case the control strategy needs a modification, it can be configured by the DATABASE, SAMA offline and then loaded to the standby station. The updated strategy will not become active until the standby station turns to be the master station. If any fault of the updated control strategy is detected, the status of the stations can be restored to the original status for ensuring security.
6. Monitoring of LN 2000 System Operation
6.1 General
The main task of the operator station is to monitor the real-time production process. The platforms in the LN2000system for running the monitoring function are the applications such as the System Management (STARTUP), monitoring View (OPTVIEW), Alarm (ALARM), Trend (TREND) and Self-diagnosis (SELFTEST). The operator is capable of monitoring the production process via these software and controlling on an accurate, quick and convenient basis.
6.2 Monitoring pictures
The production process is mainly monitored and controlled via the Monitoring pictures. The operation habit of the operators has been fully considered in the software design of the Monitoring pictures. The software is firstly characterized by its clear hierarchical structure, reasonable layout and striking display, and secondly by its abundant content, easily-called graphics and lively provided multiplayer display for the parameters and graphics of the production process, system and operation status.
The refreshing interval of the real-time data on the Monitoring Picture is 0.5 second. In spite of the operating time of the actuators, the period is not more than 2 second from the moment the operator pushes the button till the feedback information from the actuators is displayed. The display capacity, the pixels in a graphic/picture and the number of process points (analog and digital) in a picture that can be dynamically updated and controlled are depending on the speed and memory of the computer utilized for the operator station. The number can be decreased or increased as per the requirements of the operation and control of a unit. The example of monitoring picture is shown in Figure 6-1.
Figure 6-1: Example of the Monitoring pictures
6.3 Real-time Trend
The trend display is an important analysis tool for the industrial process. A complete set of trend functions are provided in the TREND program and the functional features of the trend can be set by the operator. Several trend windows can be activated and maximum 8 data point can be displayed in each window. The trend display example is shown in Figure 6-2.
Figure 6-2: Example of the Real Time Trend
6.4 Real-time Alarm
The function of the Real Time Alarm is to display the alarm points of the real time data in the Alarm Bar. Various filtering conditions are provided so that those alarms in accordance with the conditions will be filtered out. The example of the real time alarm is shown in Figure 6-3.
Figure 6-2: Example of the Real Time Alarm
6.5 Self-diagnosis
The Self-diagnosis application is used to monitor all the status of the whole DCS system, including those of the operator stations, engineer stations, process control stations (LN-PU), CAN network, modules and data channels, and clearly display these status in graphical illustration, providing adequate real time information of the system operation to the user. The display interface view of the Self-diagnosis application is shown in Figure 6-4.
Figure 6-4 Self-diagnosis display interface
7. Control Algorithm of the LN2000 System
7.1 General
Various control algorithm blocks, which have obvious external characteristics and reasonable size combination, are provided in the LN2000 system. It is easy to form control strategies with an apparent structure and it allows the engineer to define the control logic via external links so as to create conditions convenient for configuration and commissioning.
7.2 Control Algorithm Block of the LN2000 System
In the LN2000 system, the 93 control algorithm blocks can be divided into 9 function groups as per their functions as shown in Table 7-1.
Table 7-1 Control Algorithm Block
NO. TYPE Algorithm Block
1 I/O Analog input, analog output, digital input, digital output; numerical output, logic output, time output; inter-station analog input, inter-station analog output, inter-station digital input, inter-station digital output; inter-page analog input, inter-page analog output, inter-page digital input, inter-page digital output; logic return input, logic return output.
2 Mathematical Operation Algorithm blocks for addition, subtraction, multiplication, division, extraction, absolute value, exponent, power function, logarithm, trigonometric function, inverse trigonometric function, mathematics polynomial.
3 Logic Function AND, OR, NOT, Exclusive OR, sign judgment; RS and D flip-flop; counter, comparator, deviation alarm and point quality inspection.
4 Selection Function Selection for analog input, analog output, digital input, digital output, mean value, maximum value, minimum value and two-out-of-three digital signals selection.
5 Control Function PID algorithm, Optimized PID algorithm block, Single neuron-based adaptive control, M/A analog manual operator, M/A optimized analog manual operator, digital manual operator, specified analog value, specified digital value, lead-Lag algorithm, Step control, 8-input signals balance, 2-input signals balance, integration of 2 transmitters, integration of 3 transmitter, Equipment driver algorithm.
6 Time Function Timer, Optimized timer algorithm block, Cycle timer and Integrator
7 Linear Function Constant, pure delay, integral, differential, Continuous Transfer Function 1, Continuous Transfer Function 2, Discrete Transfer Function, Digital Signal Summator
8 Nonlinear Functions amplitude value, amplitude value alarm, speed rate, speed rate alarm, dead band, on/off, gear clearance, hysteresis loop switch, magamp and Piecewise Linear Algorithm
9 Signal Sources Step signal, Ramp signal, Sine signal, Square wave£¬saw tooth wave, broken line signal, multi-section square wave signal and random signal
7.3 Features of LN 2000 Control Algorithm Block
· Control module adopts independently created and scientific automatic sorting algorithm, conquering the disadvantages of disturbed control sequence due to configuration sequential sorting/operation.
· Clear algorithm block structure and functions make it easy to apprehend and master the system.
· Graphic configuration is adopted in the system. A control strategy can be formed by selecting related algorithms according to the requirements of logic design.
· The automatic tracking and bumpless changeover can be realized by the configuration software.
· The operation commands are directly sent to the algorithm blocks in a reliable point-to-point method. The back-up of the master and standby stations are automatically performed.
8. Storage and Retrieving of Historical Data
8.1 General
The objective of storing historical data is to save the long-term detailed operation information. In the LN2000system, the historical data includes mainly the following: periodic historical data, historical alarm record, operator’s operation recording, and SOE logging.
The software HISSTART runs on the historical record station of the LN2000 system, and collects and stores periodical historical data, historical alarm records and operator’s operation logs. The software STARTUP is used to collect and save SOE records.
Retrieving methods for historical data are:
· Access the periodic historical data by the software TREND and form the historical trend.
· Access the historical alarm records by the software ALARM and form the historical alarm.
· Access the periodic historical data by the software REPORT and form various reports, e.g. monthly report, daily report, trip record and the summary of equipment operation status.
· Access the operator’s operation recording and the SOE logging by the software EVENTLIST and form operator’s operation recording table and SOE logging table.
8.2 Storage of Historical Data
8.2.1 Storage of Periodic Historical Data, Historic Alarm and Operation Records
The storage of the periodic historical data, historical alarm and operation records is carried out by the software HISSTART.
The recording interval of the periodic historical data is 0.5second. The data files are saved in the folder: /hisdata/rec and the subfolders of this folder are defined according to the time. The files are named as per the data type and the retrieving range of the data points so that each file has an appropriate size suitable for retrieving.
Historical alarm records are saved in the folder: /hisdata/alarm while the operation records in the folder: /hisdata/optrec.
8.2.2 SOE Logging
The SOE loggings are very important analysis documents in case of unit failure. In the LN2000 system, the SOE logging files are saved in the folder /hisdata/soe by the software STARTUP. 100 events can be temporarily stored in each SOE module. The communication between the SOE modules and the process control stations is reliable without any SOE event lost.
8.3 Retrieving of Historical Data
8.3.1 Historical Trend
The retrieving of the historical trend is performed by the software TREND. Various parameters such as the coordinate of the amplitude value and time can be easily modified and saved in groups as shown in Figure 8-1.
Figure 8-1: Example of the Historical trend
8.3.2 Historical Alarm
The alarm at any moment in the historical recording can be retrieved by the software ALARM. The alarm interface is shown in Figure 8-2.
Figure 8-2: Historical Alarm
8.3.3 Report
Through the software REPORT, the reports, such as monthly report, daily report, trip records and the summary of equipment operation records, can be conveniently configured. The configuration interface is shown in Figure 8-3.
The configuration report can be saved & printed. The interface of a report is shown in Figure 8-4.
Figure 8-3 Report Configuration View
Figure 8-4 Report Interface
8.3.4 Operation Recording
All the items and exact time of the operator’s actions are logged in the LN2000 system. A binary encrypt format is adopted for the operation logs avoiding unintended deletion. The recording can be retrieved through the software ENTLIST as shown in Figure 8-5.
Figure 8-5 Retrieving of the Operation Recording
8.3.5 SOE Logging
As soon as the status of any point related to the SOE system is changed, the event will be logged by the SOE system including the name of the points, description, time and status. The SOE logging will be arranged according to its time sequence and printed our as per hour, minute, second and millisecond. The example for retrieving logging by the software EVENTLIST is shown in Figure 8-6.
Figure 8-6: Retrieving of the SOE Logging
9. Function Realization of the LN2000 SOE System
9.1 General
The SOE system is a part of the LN2000 DCS which provides high speed sequence logging functions with a time resolution no more than 1ms. All the events are logged as per the same time standard which is provided by the GPS module. The SOE logging contains the status and description of the detected point. The SOE logging will be arranged in accordance with its time sequence and printed out as per hour, minute, second and millisecond.
· The SOE system has the following functions:
· Collect and save SOE data at any moment;
· The SOE module has all the same functions as a DI module;
· The historical data in the SOE report can be retrieved at any moment;
· The SOE module can be installed in any process control cabinet.
9.2 SOE System Philosophy
The structure of the SOE system is shown in Figure 9-1. Its operating procedures are:
1) The historical station is time serviced by the GPS module via the RS-232 or RS-485 interface;
2) The upper station & all the process stations are time serviced by the historical station via the redundant Ethernet;
3) The GPS module provides time service to all SOE modules which can be installed in different PU via the CAN bus.
4) The SOE module detects the status of the field input signals at an interval of 1 ms. If any status is changed, the time will be logged after dithering-proof strobe operation.
5) After an SOE occurs, the SOE logging will be saved in the SOE module, which is transmitted to the PU via the redundant I/O bus (CANA/B), and then sent to the upper station via the redundant Ethernet.
Figure 9-1 SOE System Structure
10. Interfaces with Other Systems
10.1 General
With the development of the information technology, the distributed control system is no longer an isolated control system but an open system which is characterized by its interfaces that can be connected to other systems. Various interfaces are provided in the LN2000 system such as interfaces with the Supervisory Information System in Plant Level (SIS) and Management Information System (MIS). Different protocols can be adopted such as the standard OPC Protocol, MODBUS Protocol and even the user customerized nonstandard protocols.
10.2 OPC General Purpose Interfaces
OPC is the abbreviation of “OLE for Process Control”, which means that the OLE is applied in the field of industry control. The DCOM technology of the Microsoft Company is utilized for this general industrial computer interface.
LN2000_OPC provides a data service program with a general purpose industry control standard (OPC DA2.0) realizing the high performance data communication between the LN2000 DCS and other industrial control software and transferring the real time data of LN 2000 DCS commands to the client side program. Meanwhile it can transfer the commands coming from the client side to LN 2000 DCS. The window of the software is shown in Figure 10-1. The communication can be realized by the Ethernet.
Figure 10-1: Interface of the LN2000_OPC
10.3 Other Interfaces
The MODBUS Protocol based interface is provided in the LN2000 system, available for communication by using RS-232 or RS-485.
11. Hardware Installation of the LN2000 System
11.1 General
All the hardwares of the LN2000 system are installed in a standard control cabinet. Apart form these cabinets where process control station and I/O modules are installed, there are relay cabinet and system power distribution cabinet as well. Normally, these cabinets have the same dimensions and appearance. Furthermore, special cabinets can be ordered as per the requirements of the customer.
11.2 Dimensions and Installation of the Cabinet
Dimension: 800.0 mm (W) 600.0 mm (D) 2260 mm (H)
The dimensions of the cabinet are shown in Figure 11-1 and the installation dimensions are in Figure 11-2.
Figure 11-1 Dimension of the Cabinet
Figure 11-2 Installation Dimension of the Cabinet
11.3 Internal Layout of the Process Control Cabinet
Dual redundant process control stations, dual redundant 24VDC power supplies, 52 I/O modules or relay boards can be installed in a process control cabinet. The arrangement is shown in Figure 11-3.
Figure 11-3 Arrangement inside of the Process Control Cabinet
11.4 Internal Arrangement of Relay Cabinet
Dual redundant 24VDC power supplies and 52 relay boards can be installed in a relay cabinet. The relay boards and the DO modules are connected by prefabricated cables. The arrangement is shown in Figure 11-4.
Figure 11-4 Internal Arrangement of the Relay Cabinet
11.5 Distribution Scheme
The LN2000 system requires dual independent 220 V AC power supplies on site.
The dual independent 220 V AC power supplies are distributed to individual cabinets via the distribution circuit in the distribution cabinet and used as the power supply for the DC power supplies and part of the digital outputs. In case of failure of one supply circuit, it will be changed to the other power supply to maintain normal operation and a power failure alarm will be initiated for timely maintenance.
Requirements for System Power Supply:
Voltage: 220VAC ±10%
Frequency: 50Hz±2Hz
Distortion Rate of Sinusoidal Waveform: The sum of the harmonics component of all orders should be less the 5% of the fundamental component.
The maximum amplitude value superposed on the Sinusoidal Waveform by the transient voltage pulses and surge voltages should be less than 100V in a period less than tens of microseconds to hundreds of microseconds
11.6 System Grounding Requirement
To ensure the normal operation of the LN2000 system, the grounding design and installation should comply with the following principles:
¯ Only one grounding point is required for the grounding system of the LN2000 system.
¯ The resistance of the grounding copper plate should be no more than 2.5Ω, 1Ω is the best.
¯ The cabinet and the channel steel for fixing cabinet base must be insulated.
¯ The grounding system should not be connected to the grounding point of the high voltage equipment.
¯ The non-system equipment should not be grounded via the LN 2000 grounding system.
