Decentralized data acquisition - Keeping the pump plant running


Decentralized data acquisition and autonomous monitoring of distributed measuring points, including networking options, is becoming an increasingly important component for keeping an eye on the status of systems and machines, even remotely. The Ennepetal municipal sewage company has now also faced this challenge. For the monitoring of the pumping stations, they rely on a measurement data acquisition concept from Delphin Technology, which makes them fit for the future.

Stadtentwässerungsbetriebe Ennepetal operates 18 pumping stations spread across the entire city. The fill levels of the pump sumps and the operating status of the pumps are monitored at the respective stations. Two pumps at a time are controlled via a programmable logic controller (PLC) in alternating operation in order to be able to optimally regulate the inflows and outflows in the overall system. This serves to ensure the operational safety of the sewer systems and must be monitored around the clock in order to be able to react as quickly as possible in the event of faults caused by blockages or problems with the pumps, for example. Until now, the relevant data was transmitted to the service technicians via the 3G mobile network. Due to the planned shutdown of 3G and the update to LTE (4G), the measurement data acquisition was upgraded to a future-proof level with the help of the compact Loggito loggers from Delphin Technology AG.


To ensure autonomous measurement data acquisition, a Loggito logger was initially installed in each of the 18 pumping stations. With the help of the high-precision and universally usable sensor inputs, the required sensors for fill levels, current consumption, operating data and fault messages could be connected without any problems. In combination with the internal monitoring and calculation channels as well as the operating hours counters, the recorded process data not only provides information on the current status of the pumping stations, but also on the expected time for maintenance. This enables predictive maintenance of the pumping stations. The pumps can be optimally and predictively maintained and downtimes can be prevented. All signals are pre-processed, monitored and stored in the Loggito logger before being forwarded to the central data server.


The PC-independent operation of the Loggito logger with its internal data memory also guarantees a high level of data security with regard to remote data transmission. In the event of a temporary failure of the mobile network connection or a fault on the central server, all recorded data can be stored in the internal data memory. As soon as the mobile network and the server are available again, remote data transmission to the server continues fully automatically and without user intervention. This means that no data is lost and the measurement database on the server is completely filled. The independent pre-processing, monitoring and analysis of all signals with the Loggito loggers at the respective pumping station enables independent monitoring including automatic shutdown functions. Even if there is temporarily no radio connection to the respective pumping station, such functions are guaranteed at all times thanks to the autonomous mode of operation. If, for example, the limit value for the storage temperature or the power consumption of a pump is exceeded, the system can be switched off using the digital outputs of the logger.


In addition to the Loggito loggers, LTE routers with powerful antennas were also installed on site at the pumping stations to send the decentrally recorded measurement data to the central server via LTE. The routers are equipped with an automatic restart function, which re-establishes the connection and ensures remote data transmission in the event of a connection error or if the VPN gateway is unavailable. The Delphin Data Center (DDC) and the ProfiSignal 20 server are installed on the server and are responsible for central measurement data management and user administration. All data collected from the 18 pumping stations is networked, centrally stored, monitored and analyzed on the server. The measurement data is archived in a valid and traceable manner and can be retrieved at any time with access within seconds, whether on the network, via PC or mobile via smartphone or tablet.


All pumping stations can be centrally networked with each other. This also enables a comparison and in-depth analysis of the individual pumping stations. The transmission of the measurement data to end devices of the city of Ennepetal is realized within a secure network via VPN tunnel. The connection to the individual loggers and the status of each measuring point are also monitored centrally and automatic e-mail alerts are sent. As the DataService runs on the server as a Windows service, it is independent of a user login in the operating system and the alarm function via e-mail is available at all times. Employees can access the DataCenter via an OpenVPN client. Smartphones and tablets can also access the PS20 server and the DataCenter and call up the visualization via the OpenVPN app and PS20 client app. The required PS20 app can be downloaded free of charge for iOS and Android devices from the respective App Store.


Another advantage of remote access to all pumping stations is that not only the visualization of the measured values, but also the configuration of the Loggito loggers can be carried out remotely. With the help of user administration, it is possible to clearly define which user groups can make changes to the basic system and the device configuration and which user groups only have read-only access to the system. This enables service technicians, for example, to make adjustments to limit values or the monitoring and storage of various parameters without having to spend time and effort traveling to the respective pumping station each time. This increases flexibility and saves resources at the same time.


The ProfiSignal 20 Basic software is the front end of the monitoring system and offers an interactive user interface. The platform-independent complete software for the visualization and analysis of the recorded measurement data is installed in the control room as a desktop application and can also be accessed at any time via the PS20 app on the service technicians' mobile devices. The measured values and their progression over time are displayed in measurement curves on clear dashboards. These trends make it quick and easy to view the measured values historically. An overview chart shows the status based on collective alarms for all 18 monitored pumping stations. In addition, the alarm list is displayed in tabular form on a separate chart. This means that both the service technician on the road and the office staff have access to all measurement data at all times.

decentralized data acquisition and autonomous monitoring of distributed measuring points, including networking options, is becoming an increasingly important part of keeping an eye on the status of systems and machines, even from a distance. this was also the task facing the ennepetal municipal waterworks. to monitor the pumping stations, they rely on a measurement data acquisition concept from delphin technology that makes them fit for the future.

Installation situation in the control cabinet of the pumping station


The fact that the Delphin DataCenter (DDC) bundles the data from all 18 Loggito loggers on the central server enables further expansion options for the monitoring system. It is conceivable that the pumping stations could communicate with each other, i.e. the Loggito loggers could exchange and share their data via the DataService. For example, the fill level of a downstream shaft could be queried before a pumping command is issued in the upstream structure in order to prevent overflows. The versatile interfaces, such as Modbus TCP and OPC UA, could also be used to integrate other peripherals such as frequency converters or power meters at the pumping stations into the Delphin monitoring system. Ultimately, the pumps could also be controlled via a measurement data logger from Delphin Technology AG and replace the controllers currently in use. The future expansion stages of the system therefore remain exciting.

Pictures: Delphin, Lead image eevl -, Stadtbetriebe Ennepetal

Delphin Technology AG
Lustheide 81 , 51427 Bergisch Gladbach
Phone 02204 / 97685-0

Jan Tippner, B.Eng., Head of Sales,
Delphin Technology AG, Bergisch Gladbach

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