The project includes design, procurement, installation, and operation of an integrated network system for the remote-control, remote-operation, and leak supervision of the water supply network in the city of Aetolikos. As shown in the schematic diagram, the system consists of:

The purpose of the Central Control Station is the collection of measurements from the Local Stations (LS), the real-time display, processing, and storing of this information, as well as the control and operation of the pumping station. The Central Control Station is located in the city's Town Hall, where the following are installed:

For the display of the city's hydraulic network, the display of measurements, and the computer-based remote-control of pumps, the system uses SCADA WINCC software by SIEMENS.

 

The computer receives data from the PLC through a MPI port. This data is stored in a RDBMS database and statistical files are created for each measurement. These determine the minimum and maximum limits of each measurement. Based on the statistical information, any diversions from the limits cause the alarm to go off. This is the procedure to trace any water leaks at any point of the network.

 

The above information after being stored in the computer's database, appears in the SCADA display which in our case is the WINCC by SIEMENS. This way, an archive with statistical data is available and provides information for the measurements of water supply and pressure. According to this data, the operator is in a position to define in advance the maximum and minimum rates (supply and pressure rates) of the whole system so that any divergence in the future will cause the alarm to go off.

 

Besides SCADA, the control of the water supply network and the remote-operation of pumps can also be realised through a mimic diagram which is located on the front of the automation switchboard and shows/presents the following information:

The operation of the pumps is done via three modes:

The desired operation mode can be selected through a selection switch located on the mimic diagram.

 

 

The power switchboard for pumps and chlorination pumps, as well as the automation switchboard are all located in the pumping station.

 

The water is firstly pumped and then directed for consumption. If the level consumption is low, the remaining water is stored in a tank of a 75 meters level difference from the spring. The difference, thanks to gravity, guarantees the unobtrusive water flow from the tank to consumption without the use of pumps, given that the water level supplies the whole city for a certain period of time.

 

The automation switchboard is equipped with PLC SIMATIC S7-300 and wireless communication facilities (Radio Modem with antenna). The connection between the PLC and the Radio Modem is achieved through a RS-232 serial port. The levels of spring and tank as well as the water pressure inside the central pipe are presented in four-digit digital displays. These are located on the front side of the panel in order to facilitate possible damage recovery. Pump operation is done via three modes:

The desired operation mode can be selected through a selection switch on the automation switchboard.

 

The purpose of the Local Stations is to collect and send, through the CCS radio system, analogical signals about water pressure and supply.

The Local Stations are equipped with:

The communication between the Local Stations and the Central Control Station is wireless and based on the serial communication protocol MODBUS at 9600 bps.

 

 The project was designed in 1999 and completed in 2000. Testing and delivery took place in 2001.

 

 

 

 

The above system includes the installation and operation of a remote control/remote operation system for the tanks, pumping stations, and leak stations in the water supply network, as well as the automation of Mytilene's water chlorination. It consists of:

The Telecommunications Network

 

Due to the surface morphology of the area and for the achievement of faster scanning times, the network of the 12 Local Control Stations has been split in two groups.

 

The first group consists of LCS-1, LCS-2, LCS-3, and LCS-4, which receive instructions from LCS-5 that collects all the data. The networking of the above stations is based on the MODBUS communication protocol at 9600bps. This data is then sent from LCS-5 to the CSS via a R-3964 serial communication protocol at 19200bps.

 

The remaining Local Control Stations form the second group and they are directly instructed by the CSS via the MODBUS protocol. All the above communications are wireless. In case of a radio network malfunction, there is an alternative solution for the transmission of data to the CSS through a dial-up modem. The communication between the LCSs and the CSS is done exclusively through a dial-up modem.

 

The Central Control Station (CSS) is a computer network for the supervision, central control, storage, editing, and management of data from the water supply network installations. The computers run SCADA software applications for water quality control, equipment maintenance, GIS and matematical simulation of the water network. Finally an automation switchboard equipped with PLC S7-300 is installed as well as a radio modem that receives data from the Local Control Stations.

  

 

   A WATER SUPPLY-SEWAGE-LEAKS SYSTEM FOR THE MUNICIPALITY OF CHANIA

 

The automation system consists of (9) Local Sewage Stations (LSS), 9 Local Water supply Stations (LWS) and 20 Local Leaks Stations (LLS), which divide the Municipality of Chania in 30 Zones (in order to configure the mathematical model of leaks). Communication between all stations is achieved by means of modems (Radio Modems, Leased Line Modems, Dial-up Modems) using the communication protocol 3964R. The communication system is fully cutomized; meaning that any parameter can be modified without affecting the system.

 

Every local station has two types of communication: the Primary and the Secondary. Three Radio Modems (one for the Water Supply, one for the Sewage and one for the Leaks) in the Central Control Station (CCS) are used for the circular communication (polling) between local stations and Radio Modems. Radio Modems send each time the address of the station to communicate with. In the Central station (CCS) there are equal Leased Line Modems to the number of Local stations that maintain communication through Leased Lines. Finally, in the Central station (CCS), there is a Dial-up Modem in order to perform Secondary communication between most stations (by dialing up the requested number), whenever a problem in the Primary communication is diagnosed. The only exception to the above is the Local station LWS 5 (Agios Ioannis tank), which communicates directly with the two SERVERS through a Siemens MPI cable (Multi Point Interference) due to the short distance between the Central station and the specific Local one.

 

The Water supply-Sewage-Leaks system consists of 2 "Servers" and (at least) 4 "clients" as follows:

 

In Agios Ioannis Station, 2 "servers" are installed and receive data from other stations. This data is processed, recorded, and archived into files with historical details. The two "servers" work in parallel and perform exactly the same task. They are located in a small, isolated place and they are not to be used for the operation of the system.

 

"Clients" are computer workstations that are connected to the "servers" and they are used for the supervision of the system, done by the operators. They are located in the central supervision area of the system. Two of them can be found in Agios Ioannis, one in the DEYAX headquarters and one in the Biological Purification Centre. In addition, a modem facility allows the connection of a portable PC as a Client.

 

One server has been set as the 'master', while the other server is in 'hot standby'. All Clients are connected to the 'master' server. In case of a system malfunction in the 'master' server, control is passed to the 'hot standby' server together with clients' connections.

 

A station can be displayed in SCADA as follows:

 

 

From the above display, the operator can draw useful information concerning all critical figures about the station. Some of these figures are the following:

A very important characteristic of the system is the operators ability to be aware of the situation of all stations even if they observe another station. In this case, SCADA using sound and visual alarms will lead the operator to the spot that has to be located in order to diagnose and if possible, fix any occurring errors.

 

 

 

The project includes the design and realisation of an integrated control system for the sewage draining facilities in the city of Chania.

The biological purification facilities are shown in the following screenshot:

As shown in the above screenshot, the installation is divided in 24 sections.

 

The automation process of the above installation is based on 2 PLCs by Siemens (S7-400 and S7-300 types). The S7-400 and S7-300 receive signals from 22 sections and 2 sections respectively.

 

A Siemens WinCC Scada system has been selected for the supervision and remote-operation of the system.

The network consists of 2 Servers and 5 Clients:

The Servers' communication with the PLCs is done via separate multi-communication MPI cables. The PLCs receive signals from level sensors, supply gauges, pump protection units, operation indicators, PH, conductivity and temperature gauges, which are then sent to both Servers simultaneously through the MPI cables.

 

The 2 Servers collect data from all sections. This is processed, recorded, and archived into files with historical details. The two "servers" work in parallel and they are not used for the operation of the system.

The Clients are computer workstations connected to the Servers for system monitoring and remote-operation by the operators. Four Clients are located in the Central Control Station of the Biological Purification facilities and one Client is located in DEYAX's headquarters. In addition, a modem facility allows the connection of a portable PC as a Client.

 

One server has been set as the 'master', while the other server is in 'hot standby'. All Clients are connected to the 'master' server. In case of a system malfunction in the 'master' server, control is passed to the 'hot standby' server together with clients' connections.

 

An example of one section is shown in the following screenshot:

The Scada displays information about:

The operators are able to monitor on each display all system alarms in total or independently for a selected section. They can also start/stop any remote-operated unit and fix any occurred errors. Some alarms produce a sound signal through the computer's speakers in order to attract the operator's attention. Each operator is equipped with two beepers which are activated by specific system alarms. In order to determine which alarm has activated beeper 1 or beeper 2, an operator has to check the Scada alarm display. All system malfunctions can be printed.

 

All analogical mesurements and the number of starts/stops are recorded on day, month, and year based archives. These records are presented in table and curve formats. Easy access to the archives and report printing are supported for all operators. Furthermore, operators are able to modify system parameters, view online help files about the system operation and the electrical/mechanical data for each section. 15 users with different access rights can control the system. The set of system operations for each user is determined by the user's name and password. This way, unauthorised use of the system is not allowed.

 

 

The Athens Brewery plant was built in Patras in the early '80s and is the biggest of the company's three breweries in Greece. The company decided to upgrade the production control and monitoring procedures, aiming to improve quality, increase reliability, provide ease of maintenance, reduce production costs and increase competitiveness. This project was assigned to TEKA Systems.

 

The malt procedure is the first stage of beer making. The rest of the stages are as follows:

1. Weighing of the collected amount of barley, predefinition and precleansing.

2. Barley cleansing and selection.

3. Weighing of cleansed barley.

4. Watering.

5. Germination.

6. Drying.

7. Malt cleansing.

8. Weighing of cleansed barley.

9. Powder Extraction.

Stages 1, 2, 3, 7, 8, and 9 are performed in the multi-floor installation. Stages 4, 5, and 6 take place in special installations: Watering, Germination, and Drying.

 

In each of the above four installations, a technologically integrated automation system consisting of electrological automation switchboards, programmable logic controllers and computers with SCADA systems has been designed, developed, installed, and put in operation. The respective four systems have been linked to ensure the production procedures in all the aforementioned stages.

 

Materials Used:

1. Twenty two switchboard fields.

2. Ten Siemens S7-300 PLCs with extra ten extensions ET200.

3. Three inverters.

4. Five computers.

5. MPI, profibus, and TCP/IP networks.

6. Two printers.

7. Eight PID controllers.

 

All conditions of motors operations, pumps and valves, marginal positions, rates of analogical sizes, outnumbers of marginal and critical setpoints are monitored in real time, giving absolute and reliable knowledge of all the production parameters.

 

All system conducts, like for example sporadic motion of motor, valves and pumps, definition of marginal setpoints and the execution of other works including whole sectors of the existing installation, are capable of being performed having as compass security and liability, since wrong manipulations are automatically aborted by the system. Two operation modes exist in the system: the manual operation during which, it is the operator that commands all operations and the automatic operation which is considered the normal operation condition. The automatic operation is based on the batch processing principle. It is achieved by means of many customised formuli that consist of several stages. Their number can be increased only by licensed operators - supervisors. During the automatic program performance, the operator is exclusively charged with surveillance of the parameters of the formuli and has the right to interfere by changing a rate whenever a deviation (either due to an engineering miss or an unforeseen change of exterior conditions such as temperature and humidity) from the desired result is detected.

 

All operations (manual or automatic), any changes in parameters of the automatic program, changes of the operation condition, damages, alarms and analogical rates are registered in every production section and are presented to the operator in a transparent and intelligible manner through the use of diagrams and alphanumerical fields. The completion of every production stage is accompanied by an automatic completion of an appropriate report that is printed and kept in the archive. The system maintains information (data - diagrams) about fardels for more than one year.

 

The computers, which are responsible for the maintenance of the communication between the system and the operator are connected via a LAN net (TCP/IP). Each computer that has access to the specific net through proper software and access licenses, can be connected to the production procedure, providing this way to the malt-making section the possibility to be connected to the other parts of the plant. Thanks to the above system, an automatic and more reliable connection to the next production stage (brewing) can be achieved. Simultaneously, the executive managers (e.g. production management) are able to directly update and supervise production.

 

The advantages from the installation and operation of the above integrated automation system for the Athens Brewery can be summarised as follows:

1. Improved Quality.

2. Improved water and energy consumption.

3. Reductions in the personnel's workload and extinction of operational errors.

4. Customisation of the procedures and better understanding of the various operations.

5. Ease of maintenance, including maintenance programming.

6. Error checks.

7. Increased capacity for production programming.

8. Statistical analysis and editing of the production.