Project
In the Grevesmühlen (Germany) project YP Telemetrie shows the optimal use of CARS combined with the remote-IO in a Dupline network. The main reason of comming up with the Dupline solution for this customer lies in the fact that the existing installation could remain untouched. By simply extending each substations control with the required analogue and digital input modules all of these units could be merged into the CARS telemetrical software environment.
There were requirements set that the system data should be presented in two hour intervals. This is substracted from the German ATV-DVWK-M260 directives which describes the common presentation and archieving of wastewater treatment variables. Because of the flexible application of the CARS software these requirements could be met without consessions.
Location
In 1992 the initial step was taken in the project for the complete control and monitoring of the wastewater treatment system as the local SCADA system on the Grevesmühlen sewage works was taken into use.
And as the central sludge treatment at the Grevesmühlen sewage works was taken in use, in 2002, the second fase had been completed.
On the third and final fase, all sewage works (SW Grevesmühlen, SW Boltenhagen, SW Dassow and SW Lüdersdorf) will be merged to one system controlled from the Grevesmühlen location.
All process variables and event data that is gained throughout the complete installation will be logged, edited, analysed and archived on the central location. By having a centralized system like this it will become possible to quickly react on system failures and threshold overflows of unmanned stations or works. By automatic notification of the service team or implementing automated failure actions a very reliable and sufficient system is created.
Partner
The project was initiated by Siemens Germany of whom the Zweckverband Grevesmühlen had been a satisfied customer for a long time.
Features
Dupline® fieldbus
In order to leave the original control untouched, all substations were extended with Dupline fieldbus input modules. This enables the reading of substation variables, digital or analoge, from a remote location up to 10 km using a simple two wire connection and even without the use of repeaters.
Since some locations were uninterresting to connect by means of a direct signal cable, a CARS Module was used to create a so called subcentral communication point. Each location consists of a Dupline master module and a CARS Unit which is hooked up to a regular phone line or the GSM network.
The substations in each network can be connected in every desired way, as branche-, star- or mixed networks. This shows the extreme user friendly and flexible application of this fieldbus system.
CARS Module
The CARS Modules which are installed on the subcentral communication points provide a cost effective link between the CARS software and the Dupline substation IO.
All possible alarms that may occur in the installation are send to the main station immediately in a secure and reliable way. Even on loss of the supply voltage the messages are forwarded to the mainstation at once. Including the local 'loss of supply voltage'-message.
In case the mainstation software should be down, for whatever reason, the CARS module will retry sending its message(s) as many times as the user defined it to. When all retries fail a text message will be send to a service mechanicor informing on the communication problems between the main- and the substation. This way a waterproof message system has been created providing the maximum system availability.
The communication check works the other way around as well. Each time the CARS Mainstation starts the procedure of fetching logged data and the communication with the desired CARS Module can not be created, a text message is send to the service mechanicer as well defining a clear problem description.
Summary
- Dupline® fielbus
- CARS Module
Combining powerfull and flexible systems as the Dupline fieldbus equipment and the CARS Mainstation software will lead to the most cost effective and reliable solutions for a wide range of applications where remote control and monitoring is required. The project described above is just a single step in the direction of the applications these systems open up to.
