EPAL - Lisbon Water Supply

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1 EPAL - Lisbon Water Supply CitectSCADA s redundancy and real-time control optimize supply THE CHALLENGE Divide the existing EPAL Command Centre in two whilst ensuring compatible integration of all PLCs, guaranteeing redundancy throughout the systems and display refresh times of <3 secs. THE SOLUTION Tecnilab Portugal based the whole systems at the 2 new Command Centres on CitectSCADA with Microsoft Windows NT Server and Windows NT Workstation providing the operating system. In order to guarantee maximum project reliability, Tecnilab used Citect s technical support, and consultants based in Portugal to evaluate and set the guidelines. THE CHALLENGE EPAL, (Empresa Portuguesa de Águas Livres), is the successor to the Lisbon Water Supply Company which has been in charge of water supply to Lisbon since Its daily production is sold directly to approximately 330,000 domestic consumers throughout Lisbon and indirectly through municipal services and distributors to 23 neighbouring municipalities. The total population serviced is approximately 3.1 million inhabitants. With over 100 years experience in carrying out this essential service, EPAL holds the most important water production and distribution structure in Portugal. It manages three sub-systems with the following production capacities: Water spring of 70,000 m 3 /day Underground catchments of 270,000 m 3 /day Surface catchments of 740,000 m 3 /day In the 80s, EPAL approved an international tender process for a project to implement a Telemanagement System. The project objectives included centralizing the command for catchment, delivery, treatment and distribution, to have real-time and local control of all processes and to increase the security of equipment operations, data storage and exploitation balances. In order to reach these goals, the following preparation work was carried out: 1. New sensors and final command systems were installed in the command stations and integrated with the existing equipment. 2. A new PLC was installed in each station for data acquisition, communications management and local control. 3. Command Centres were commissioned along with supporting software and hardware Further to this restructuring, in 2002 EPAL created two major business areas within the company which divided the existing CONCLUSION With CitectSCADA, Tecnilab has provided EPAL with realtime control over the whole network in its 2 new command centres. EPAL has been delivered a reliable solution which lowers life-cycle costs by improving operator efficiency and by being easy to maintain. Business decisions have been made easier with better reporting data for process evaluation. Overall EPAL has lowered its total cost of assets rk and guaranteed redundancy, compatability and display refresh times of 1.5 seconds on average. CaseStudy

2 With Citect s technical support, Tecnilab Command Centre in two. One was concerned with water production, transportation and distribution of water to the municipalities north of Lisbon, whilst the other dealt with the water distribution system to direct consumers south of Lisbon. Tecnilab Portugal with CitectSCADA was chosen for the integration of the application because they offered the best solution both technically and economically. CitectSCADA offers proven network architecture and all over redundancy combined with the ability to meet all of the customer s requirements in terms of alarms, trends, reports, language, calculations, commands and response times. REQUIREMENTS The old EPAL telemanagement system ran on DEC ALFA AXP computers, working in hotstandby, using OSF-1 as the operating system. The reports were processed in a sole computer. Generally, the old system showed slow response times in its supervision, and was limited in terms of expansion. The development project involved: Dividing the existing EPAL centre into 2 Command Centres Guaranteeing compatibility with the existing field PLCs Integrating all PLCs via optic fibre network Guaranteeing redundancy in the system s main services including: communications, alarms, trends and reports and all the supervisory sytems services Maintaining the existing reporting systems and implementing new ones, by guaranteeing their redundancy Including new communication lines in order to guarantee communications redundancy throughout the installations Maintaining the existing graphic interface structure and integrating new functionalities at command centre level Guaranteeing display refresh times of <3 secs Integrating the existing projection systems Allowing the inter-connection of the 2 command centres The deadline for developing the system, was 5 months for the Distribution System and a further 2 months for the Production and Transport System. THE SOLUTION PC machines were chosen as the architecture of the new system, for all the servers and clients. Servers above the multi-processor level showed reliability, reinforced by redundant discs with mirroring as well as redundant feeding sources and ventilation. The main servers were based at the multi-processor level with redundant hard disks and redundant power supplies. The whole system is based on CitectSCADA with Microsoft Windows NT Server and Windows NT Workstation providing the operating system. Microsoft SQL Server is the database and Visual Basic, (VB), is used for reports. EPAL looks after the water supply to over 3 miilion consumers both in and around the city of Lisbon, Portugal. The project was developed by a group of 6 engineers, responsible for Project Management, Project Architecture, PLC Programming, Communications analysis, Configuration of CitectSCADA and SQL, VB Programming, Network and Computer hardware, System Testing and Commissioning and training.

3 guaranteed maximum project reliability In order to guarantee maximum project reliability, Tecnilab counted on Citect s technical support, and on its consultants based in Portugal to evaluate and outline some of the guidelines. Supervisory System CitectSCADA offered a solution to the peculiarities that the system displayed: Service distribution through several servers Redundancy of each of the communication services, alarms and trends A communication capacity higher than 16 RS-232 ports, with redundancy for each piece of communication equipment Communications protocol compatible with existing PLCs Redundancy of up to 4 Ethernet networks Excellent graphic capacities for interface with the operator Displays with automatic adjustment when re-dimensioned to allow various displays on the same screen Using one project alone for all the computers, with redundancy in the access Allowing various technicians to work simultaneously on the same project Scalability allowing the system to be expanded to incorporate other servers and clients and to be accessed via Internet Bearing in mind the short development time frame for this project, CitectSCADA contributed majorly to the success through allowing various technicians to work simultaneously on the same project, and allowing the re-utilization of resources such as animated objects, (Genies and Super-genies), and Templates. Communications To improve response times with the PLCs, all the communication frontals were replaced by Port Servers with 16 and 32 RS-232 ports each. Some modems were swapped in order to increase the communication speed in certain lines. Some 7 I/O servers are used in the whole project and are exclusive to communications, with 6 of the 7 servers being redundant. The response times achieved were less than 2 seconds. The biggest speed limitations found were on the EPAL Alta Command Centre, where some communications were run through Radio at 1200 bps. This is being replaced with bps hertzien waves. CitectSCADA demonstrated that a system s response time depends on the speed of the PLCs and the delayed times on the communication equipment units. By using Port Servers with more that 20 ports, there is no loss in performance at the communication level. The use of the redundant I/O servers means that many of the functionalities are assured. Any communications fault with the equipment allows that equipment to be accessed through a second I/O server. In this way the redundancy EPAL operating centre EPAL main display

4 of the equipment is assured. In case the I/O server itself stops working, the redundant I/O server automatically initiates the management of communications with all field equipment. In order not to waste resources, it is possible to divide the system load into the two I/O Servers, maintaining a more balanced system and assuring the total redundancy of communications in case of failure of one of the I/O servers. Should a communications fault occur, the transfer time between I/O servers is significantly reduced, enabling the network clients to continue without being inconvenienced. Graphic Interface The required graphic interface is very rich in information. The general displays often exceed 1000 animation points. There is direct access to any controllable equipment from the general displays. The displays allow the operator to navigate inside the installations obtaining detailed information such as the number of manouevres of a valve or the amount of energy consumption. The equipment itself allows direct access to the command display of the respective equipment. The whole PLC network is represented in several displays showing the status of each communication line. Any animation which uses information sourced from a PLC with faulty communication, appears with a grill on top of it. In this way the operator knows that the information is invalid. Alarms There are 2 redundant servers in each centre to process the alarms. In case of a server failure, the second server takes on the alarm process. Any equipment under alarm indicates the alarm by colour. The analogue gauges also show alarm information, allowing the operator to change the alarm set points whenever necessary. The alarms can be recognized individually or collectively, and the last 3 alarms are always displayed. The operator can check the alarm records and events, as well as define filters to select information by date, hour, type, value, operator, etc. Trend Analysis There are 2 redundant servers in each command centre to process the trends. In case of the failure of one server, the second server takes on the data processing and recording. When the faulty server is replaced in the system, the history of the information that it lost whilst out of service, is automatically backfilled. This way, the 2 servers are always synchronized. To enable flexible trend analysis, the operator can group the existing variables in a maximum of 8 per graph, and record any created scenario, including sample collection and ends of scale. In this way the groupings, necessary for the exploration phase, can be created, without the need for creating additional displays. The graphic interface is rich in information During analysis, the operator can navigate in time, check the value of each variable for each time period, add and remove variables, carry out zooming, change the scale and print, or

5 The reports process information goes into detail about flows, pressures, energy consumption, operating times, conductivity, ph, turbidity, weight and other information export to Excel. All trends can also be copied and replaced in the system for future analysis. Reports When integrating the reports to the new system, the SQL server gave a positive response to the processing of over 5 million records. Before any development, Tecnilab tested some analytical tools and other software modules for report generation based on a database, but for EPAL, the only solution was to develop new software to generate all the reports The report engine was developed in Visual Basic with SQL Server, and generates any kind of report for EPAL, in run-time. There are over 50 reports, each report being one to several pages in length, with daily, monthly and annual checking possibilities. The reports are stored in 2 redundant servers, allowing the operators to consult each of the servers. The reports process information goes into detail about flows, pressures, energy consumption, operating times, conductivity, ph, turbidity, weight and other information. Stored on an hourly basis, the reports present information in several ways including: values of sample collections in the period; variations in the period, accumulated totals as well as various calculations such as: power factor; maximum; minimum; averages; totals, specific consumption and variations against previous reports, functioning times etc. Apart from the main body of the report, there is, presented in the lower area, a set of summary information of the whole report, incorporating summarized tables obtained from direct access to databases or calculation formulas. All reports are run-time generated and processed, enabling more simplified maintenance both in the alteration and in the implementation of new reports. Any report can be exported to Excel or HTML. During data acquisition for the primary server, a data replica is made to the secondary server. In case of a primary server breakdown the data go on to be recorded in the secondary server, thus guaranteeing redundancy in the data access and processing for the reports.

6 CONCLUSION With CitectSCADA, Tecnilab has provided EPAL with real-time control over the whole network in its 2 new command centres. EPAL has been delivered a reliable solution which lowers life-cycle by improving operator efficiency and by being easy to maintain. Business decisions about delivery, treatment and distribution havebeen improved with better reporting data for process evaluation. Redundant services, communication and network architecture resolve any operational failure issues. Overall EPAL has lowered its total cost of assets rk and guaranteed redundancy, compatability and display refresh times of 1.5 seconds on average. This article was writen by Luis Ribeiro, Systems Engineer, Tecnilab Portugal. To contact Tecnilab: Tel: tecnica@tecnilab.pt EPAL Final set up of 2 EPAL Command Centres Statistics CitectSCADA version 5.31 Operating system Windows NT Server and NT Workstation Total no. of computers 27 I/O Servers 7 Alarm and Trend Servers 4 Display Clients 10 Manager Clients 2 Report Servers with SQL Server 4 Digital Alarms 17,530 Historical Trends 1,512 Citect Displays 762 Tags 37,392 Reports 58 reporting formats in a total of 102 sheets No. of PLCs 106 Updating of displays (average) 1.5 secs Command response (average) < 1 sec Checking of one report (average) 3 secs PLC Brands Saia Sign up for your free monthly MyCitect News for the latest e-news on product and driver developments and application stories in your industry. Visit today! For further information visit or call your regional office AMERICAS Toll-free CITECT1 AUSTRALIA Tel EUROPE Tel CHINA Tel SOUTH AFRICA Tel Copyright 2002 Citect Pty Ltd. All rights reserved. Citect and Plant2Business are registered trademarks of Citect Pty Ltd (formerly Ci Technologies Pty Ltd). All other brands or names are property of their respective holders.