4-20mA industrial sensor outputs could help IoT efforts

Wolfgang Thieme, BehrTech
Wolfgang Thieme, Chief Product Officer at BehrTech (BehrTech)

The Internet of Things (IoT) has garnered significant traction in 2019, and it shows no sign of slowing down. Amid security concerns, complexity and technical challenges, IoT implementation proves to be unstoppable. According to a new study by Microsoft, 85 percent of enterprises reported having IoT adoption underway, with 88 percent of adopters believing that IoT is critical to their overall success. As IoT continues to drive innovation initiatives across business sectors, we see a continued effort to gather data from legacy systems by harnessing 4-20mA industrial sensor outputs.

The concerted effort in gathering data from legacy systems will continue in 2020, since a hefty upfront investment makes a “rip-and-replace” approach to Industrial IoT mostly infeasible. Sensors have been widely used in enclosed industrial networks to measure and report critical variables to a local controller for automation and control tasks. As such, hooking them up to the IoT will open immense possibilities for better operational oversight and planning, especially when it comes to remote assets and systems.

RELATED: IIoT deployments only half successful: study

The 4-20mA current loop is a versatile analog signaling standard extensively adopted in brownfield industrial sensors. In a current loop, process variables (e.g. temperature, pressure, etc.) gathered by the sensors are converted into a proportional current value between 4 and 20mA. These signals are then sent to the process controller via wiring to trigger responses on actuators. While versatile for process controls, current loop sensors pose the challenge that data from the sensors are not readily accessible to all parts of an organization, a creating what are known as "data silos." Manufacturers, therefore, fail to get a comprehensive picture of what’s happening in their processes.

A retrofit IoT solution could help overcome this challenge by adding wireless connectivity to 4-20 mA devices. An IoT wireless transmitter embedded with 4-20 mA interfaces can draw process data from field sensors and send it to a remote base station using long-range IoT connectivity. Besides minimizing cabling, such a solution offers the benefit of power independence because the transmitter can operate on batteries that last for years. This allows easy wide-scale deployment to gather vast data from remote legacy assets and equipment—at drastically reduced costs and complexity.

Wolfgang Thieme is the Chief Product Officer at BehrTech, an enabler of next-gen wireless connectivity for Industrial IoT. He has more than 12 years of experience in academic research and development, successfully innovating and implementing new technologies with commercial partners and managing development and product teams.