Customer application 26 April 2018
Water Resource Management: Intelligently Networking Measurement Values

NIVUS and WAGO have created a simple network using a standardized solution.

The importance of using the right measurements comes up again and again when processes need to be optimized. That may sound easy, but it is often quite the opposite. Using the right measurements means determining what data is actually relevant for the process analysis, evaluating it with suitable mathematical models and contextualizing it constructively. If this succeeds, then it is possible to derive steps with the potential to permanently increase the efficiency of the process. In wastewater treatment, data is primarily recorded in the sewer system or at wastewater treatment plants. NIVUS GmbH from Eppingen, Baden-Württemberg, is among the market leaders in this sector with their measurement sensors. Together with WAGO, the company developed a solution that links data from distant stations into a network in a comparatively easy way.

Wastewater treatment facilities are sensitive systems involving microorganisms that require uniform conditions. In this context, harmonizing the wastewater inflow is essential – particularly in terms of the volume, concentration and composition of the waste load. This can be achieved by combining the flow measurements of the wastewater in the sewer system with hydraulic engineering systems, such as a throttle point.

If the individual measuring stations of the hydraulic engineering systems are networked within a sewer system, the data obtained here is available in real time at the control center of the wastewater treatment plant. By comparing the setpoints and actual values for the process data from the wastewater treatment facility, it is possible to calculate the optimal wastewater inflow mathematically and ensure optimal plant operation. When calculating the necessary measures, it is necessary to also consider the delay between when the settings are modified and when the changes take effect. Thus the process control begins long before the load even arrives at the wastewater treatment plant or even its individual zones. At the same time, targeted control of throttle points and other hydraulic engineering systems can make an important contribution to surface water management. NIVUS describes this approach as an integrated process control system which forms the basis for further development towards the goal of “Water 4.0.”

The Benefits of WAGO for You:

Continuous system monitoring with the PFC200 Controller
Early identification of sources of interference
Targeted acquisition and evaluation of process values with the WAGO I/O SYSTEM 750/753

Optimal Process Control

Buffer storage systems, such as underground stormwater retention basins in the sewer network of a disposal area, also require efficient control. These can fill up completely during heavy rain and, as the rain tapers off, can provide a quantity of water with a low contamination load that is optimal for the biological processes at the treatment facility. Furthermore, the discharge valves of these basis can be adjusted as needed on the basis of the intelligent system network. The benefit is smooth purification processes that allow good discharge values at increased energy efficiency.

Standardized Solution, Complex Application

The majority of the many applications used in water technology and wastewater treatment systems are used in recurring tasks. Therefore, NIVUS and WAGO developed a standardized technology for them. The 750 Series WAGO I/O SYSTEM with a PFC200 plays the central role of a maintenance-free IoT gateway in the substations. As the NivuLink Control, it provides the connections between sensors, actuators and control center. NIVUS thus combines automation of the centralized processing facility with monitoring of the decentralized, distributed processing areas. The resulting advantages are obvious: “There is one central operator interface that extends down to the lowest level. The distributed stations are monitored and controlled from a central point. The centralized visualization of sections of the system helps users get an overview quickly and enables them to monitor and control distributed systems efficiently,” explains Martin Müller, Marketing Manager at NIVUS. Processing them in the controller and then forwarding them to the control center via TCP/IP as a bundled data packet

Easy Connection of Decentralized Stations

The decentralized controllers, which are installed at distributed points throughout entire system, control the process while also monitoring the system. Via PFC200, a pump station be linked to and controlled from the control center, and the system can also be monitored continuously. With this approach, problems like wear or blockages can be identified and addressed at an early stage. With more than 500 function modules, the 750 Series WAGO I/O SYSTEM provides the hardware platform for linking various sensors and measuring technologies, as well as drives. This allows the process values to be recorded in a targeted way at the substations and then evaluated.

Thus Martin Müller is justified in describing the PFC200 “as the remote brain that links the sensors to the control system – and ideally, we provide both the sensors and the control system.” This integrated solution provides an overview of the wastewater treatment system at all times. This reduces labor costs for system monitoring and maintenance while also increasing operational safety.

“The process values measured at the substations allow targeted conclusions to be drawn about the state of the system as a whole. The system solution using NICOS and the PFC200 or NivuLink Control represents an important step towards predictive maintenance for the operators,” emphasizes Kay Miller, Global Industry Manager for Water at WAGO. The general openness of the I/O System 750 paves the way for collecting a huge variety of analysis values, signal types or data formats with suitable I/O modules, processing them in the controller and then forwarding them to the control center via TCP/IP as a bundled data packet.

Connection without Limit

In addition, the many interfaces included in the WAGO I/O SYSTEM 750 facilitate communication with nearby machines and system components. Analog and digital outputs, as well as bus technologies, are available for controlling actuators. The measured value memory storage in the device can be easily expanded with SD cards. The connection to higher-level systems can be conventional, using via existing data lines, or wireless, using the 3G version of the PFC200. “By further developing the PFC200 to create the NivuLink Control, NIVUS has created a solution whose use is independent of network availability or specific SIM cards. It offers a choice between server-based and cloud-based applications,” explains Kay Miller. The NivuLink Control, based on the PFC200, features minimal data volumes, thus reducing data transmission costs. Alarm and trigger functions accelerate processes in predefined scenarios. Integrated security features like OVPN, IPsec, or TLS are used to ensure transmission security. Therefore, the NivuLink Control also meets the cybersecurity requirements of critical infrastructure applications.

Conclusion

In NIVUS’s experience, control system manufacturers very often used to solve the problem of geographically distributed systems with heterogeneous system levels. “These don’t meet the requirements of complex technical subsystems – at least not in a single step,” explains Martin Müller. They relied on “remote terminal units” (RTUs) with low levels of automation for external stations and then combined separately-designed subsystems into the higher-level network control system in a second step. “With the NivuLink Control, we provide a single intelligent solution for completely networking sensor-based measuring systems – from a single supplier, in a single step,” says Müller.

Authors:
Martin Müller, Head of Marketing at NIVUS
Kay Miller, Global Industry Manager for Water at WAGO

About NIVUS

The NIVUS Group is a leading developer, producer and supplier of measurement technology and process control systems for water resource management. The company has developed fill-level and flow-through measurement technology for 50 years and continues to develop application-oriented measuring systems. Its solutions are characterized by a practical approach to consulting. The company is located in Eppingen, Baden-Württemberg, and is represented internationally by nine subsidiaries and more than 40 distributors.