Digitalising the production world increases the need for information between the various levels of the automation pyramid from the sensor/actuator level up to the enterprise management level with its ERP systems. Here sensors are the eyes and ears of automation technology, without whom there would be no data for such a cross-level flow of information. They are at the scene of the action in the system and provide valuable information as the basis for implementing modern production processes. This in turn allows smart maintenance or repair concepts to be identified, preventing production scrap and increasing system uptime. In combination with intelligent controllers even self-regulating systems can be identified which can be adapted in a highly dynamic way to the respective production requirements (Cyber Physical Systems, CPS).

Digitalising begins with the sensor

Digitalising therefore, requires intelligent sensors to enrich equipment models with real data and to gain clarity over equipment and production status. Furthermore, this means that the "eyes and ears" of automation have to provide additional information beyond their primary function. In addition to data for service life, load level and damage detection environmental information such as temperature, contamination or quality of the alignment with the target object are required.

With the two new photoelectric sensors in the BOS 21M series, Balluff now offers two intelligent sensors that provide such additional data. Along with the switching signal they also use IO-Link to provide valuable information about the sensor status or the current ambient conditions. They also offer a high degree of flexibility, since the sensor operating principles can be changed, making reliable detection of many different objects possible: the versatile all-rounder BOS 21M ADCAP uses red light and lets you select from among four sensor modes: background suppression, energetic diffuse, retroreflective or through-beam sensor. The high-precision laser diffuse BOS 21M HPL lets the user choose between two different modes of background suppression so that the sensor can be configured for the specific detection task and to ensure the best possible detection.

Diagnostic function for intelligent maintenance concepts

The additional sensor data lets you identify intelligent maintenance concepts in order to significantly improve system uptime. An operating hours counter is built in as an important aid for predictive maintenance. Thanks to clever diagnostics information using current values for light remission, you can detect contamination build-up, sensor misalignment, setting errors or other irregularities before they become a problem. In the laser sensor BOS 21M HPL the teach process is monitored using a plausibility check, with an error message sent as needed.

Extremely helpful in many applications are the light emission values, for example when the ambient conditions result in increased sensor contamination. These values are made available over IO-Link as raw data to be used for trend analysis, for example optimizing maintenance intervals and adapting to the actual need. Plant operators often find this essential. An excellent example of this is the production of tyres. If the transport line of freshly vulcanized tyres suddenly stops due to a dirty sensor, the tyres will bump into each other, resulting in expensive scrap as the still-soft tyres are deformed. This also results in a production stop until the transport line has been cleared, and in the worst case the promised delivery quantities will not be met. Sensors like the BOS 21M ADCAP, which provide corresponding diagnostic possibilities, quickly pay for themselves in such cases. The light remission values let the plant operator know the degree of sensor contamination so he can initiate a cleaning measure before it comes to a costly production stop.

But when it comes to operating security the intelligent sensors offer even more. The BOS 21M ADCAP is the first to directly monitor the light-output of the emitter LED. The intelligent diagnostics of the emitter output, which is represented by an easy to understand three-stage "traffic light", prevents malfunctions and reduces machine downtimes. This allows critical operating conditions caused by aging of the LED to be recognised and responded to early.

Flexible and clever

These intelligent sensors also help to relieve the burden on the host controller while at the same time reducing data traffic on the fieldbus. Both sensors pre-process the detection signals right in the sensor. An integrated count function offers various counting and reset possibilities for a wide range of applications. This decentralised sensor intelligence provides for fast processes regardless of the IO-Link data transmission speed.

Since the operating modes of the sensors can also be changed on-the-fly over IO-Link, very different objects can be detected under changing operating conditions. This makes production flexible while quickly adapting to changing requirements. Inventory is also simplified, since the BOS 21M ADCAP combines four sensor principles in one. Sensor replacement is easy and uncomplicated, since the parameter sets can be updated and loaded via IO-Link at any time. Modern production concepts and Industry 4.0 solutions benefit in many ways from these intelligent optical sensors with their pioneering functions and properties.

Balluff will be exhibiting at the Drives and Controls exhibition on the 10th-12th April. Visit the team on Stand D876 to find out more about our intelligent sensors and to learn how we can provide the correct solutions for you.