Modern industrial machinery requires an increasing number of sensors to boost their performance, and these devices have to survive in increasingly harsh environments, placing larger demands on the performance of the connectors.
At the same time, practically every application that communicates and uses data anywhere in the world is connected using optical fiber, and this combination of rugged sensors and optical networks is being driven by the needs of next generation factory automation systems and the Internet of Things (IoT).
Connectors for these systems are now required in some of the harshest environments, buried underground or installed in outdoor enclosures. Sensors on production equipment, communications masts, bridges and poles constantly transmit data to the cloud, monitoring the performance of the electronic systems as part of the IoT and Industry 4.0.
Sensing light, temperature and humidity
This means an increasing number of sensors are being designed into embedded equipment, from photoelectric for measuring distance or proximity to humidity and temperature, sending data to and from the cloud. These are feeding data back through networks of fieldbuses, bridges, gateways and repeaters channelling these vast quantities of data will require fiber optic cable connections, sometimes in very dirty environments.
Photoelectric sensors in particular can be used to detect distance, presence or absence of an object using a light transmitter and a photoelectric receiver. The latest photoelectric automation sensors for example use a diffuse reflective sensor which can be used to detect objects up to 40mm away with robust connection and cables for up to 2m to a local gateway.
These new sensors reduce the number of devices in the equipment, eliminating the need for a reflector or receiver and making the sensor sub-system smaller. Because these are fitted into harsh environments, a watertight and dustproof seal to any standard M5 interface is vital, along with robust casings that can withstands physical impact and vibrations and shocks from nearby machinery.
Temperature and humidity sensors similarly are providing more data about the performance of industrial machinery, both inside and outside the factory. Smaller, robust sensors can be designed into key spaces in equipment to flag up potential problems, from excess condensation causing rusting, to higher temperatures giving early warning of overheating in deeply embedded systems.
To be effective though, these sensors are connected to local gateways that themselves have to connect back to the cloud reliably, and fiber links are increasingly popular as they are not susceptible to the electric fields that fluctuate in such environments. Electromagnetic interference can be a major issue in industrial environments.
Protecting delicate optical fiber
Unfortunately a standard fiber connector is not sufficient for these gateways, and measures must be taken to protect the optical fiber from moisture. Compact connectors are needed to keep the local gateway small and aggregate the data from multiple sensors, but these connectors also need to survive in harsh environments.
There are several types of rugged connectors for optical links available, but for IoT and Industry 4.0 applications these have to offer standardised connection so that specialist engineers or equipment are not needed to terminate the connections.
Screw-lock mechanisms can appear to be closed when the thread is contaminated with dirt, leaving the system vulnerable to contamination. In contrast, a twist bayonet mechanism will only offer a “positive” click on closing when it is fully closed and unobstructed by contaminants.
The latest sealed standard fiber interface connectors are UV resistant, salt spray resistant and sealed to IP68 and IP69K, protecting the fiber from dirt, dust and temperature extremes (-25 to 70°C) and capable of being immersed in up to 10m of water for up to two weeks.
Water, dust, temperature and shock are key considerations for both sensors and connectors across the Internet of Things and next generation factory automation. Aggregating sensor data through rugged embedded gateways is a key part of the rollout of Industry 4.0 systems, enabled by compact, rugged sensors with reliable connectors and links back to the cloud. With the data from all these sensors safely in the cloud, embedded equipment around the globe can be more easily monitored and any problems anticipated to avoid unscheduled downtime.
For more information about Bulgin’s range of sensors for industrial automation, please visit https://www.bulgin.com/en/products/range/sensors.html