Unleashed IIoT by example of water quality

April 14, 2020 - PRLog -- The method of unleashed flashes is familiar in photography. This simple, but highly efficient method can also be applied to the Industrial Internet of Things (IIoT). Instead of restricting oneself to a package of interlinked system components from a single manufacturer, system architecture with project-specific tailored selection of components from various manufacturers offers optimum performance and that often at more favourable terms.

A simple example illustrates the interaction of hardware selection and software development. When bottles are cleaned at bottling plants, NaOH (sodium hydroxide) is also used. The use of the alkaline solution increases the pH value in waste water. As a result, the microorganisms from the biological treatment stages can no longer reduce the nitrogen compounds efficiently. In order to prevent damages to these microorganisms and additionally to water flora and fauna in general, it is necessary to constantly measure the pH value locally at different locations. To-date, these measurements are carried out manually by sewage specialists from treatment plants or external laboratories, meaning high staff, material, work and travel costs. Moreover, the actual number of measurements is restricted due to the staff resources available.

In collaboration with a measurement and control technology supplier, Acceed GmbH (Germany) developed a system for the automated recording and central evaluation of measurement data for the allocated measurement locations. In addition to the pH probes, the hardware used consists of a gateway, an industrial POC-210 series box computer, a microcontroller programmed by Acceed and software developed by Acceed to evaluate and visualise the measurement data.

The microcontroller programmed by Acceed reads the pH probe measurement values via the modbus RTU protocol. They are then transmitted to a gateway via a LoRaWAN transmission path. Thus, the data from measurement locations which are difficult to access in the sewage channel is also transmitted as energy efficiently as possible, also over long distances, at regular intervals. Depending on the sensors used, the LoRaWAN technology is also appropriated for use in ATEX environments which are subject to the restrictions of Zone 1, gas zone IIb. The data is transferred via the Ethernet from the gateway to the central series POC-210 box computer. Storage (MySQL), evaluation and visualisation (NodeRed) take place there. In addition to documentation and visualisation, it is also possible to output alarms if limit values are exceeded. Thus, the necessary sewage controls can be implemented more efficiently, audit-proof and more cheaply. Problematic pH measurement values are recognised without time delays, enabling timely and effective intervention before more serious impairment is incurred.