In addition to the sensor temperature, operating voltage and operating time, the sensors record the number of boot cycles, the switching frequency and the distance values. This information can be called up via the IO-Link interface if required and can be digitally processed directly in the control system. The sensors also have a memory: their histogram function enables the frequency distribution of the process and diagnostic data to be evaluated over a relevant period of time. In this way, information on the condition of machines and systems can be collected and evaluated for the purposes of condition monitoring. This data forms the basis for a predictive maintenance concept; specific analyses of the collected diagnostic and process data can be used to increase system effectiveness and optimize processes.

The 'AlphaProx' inductive distance sensors primarily provide a digital distance value accurate to the micrometer. With a cycle time of 0.6 ms and a switching frequency of 1.25 kHz, the inductive sensors are the fastest on the market, according to the supplier. The extensive diagnostic data mentioned above is a new addition: For example, the age of the sensor can be determined very precisely with the help of the number of boot cycles recorded or the operating time to date, enabling machine operators to draw forward-looking conclusions about when a component needs to be replaced or serviced.

The histogram function for logging process and diagnostic data makes it easier to trace faults in the event of undesirable machine states, thus shortening the fault analysis process. It is also possible to evaluate trends. For example, an increase in the sensor temperature can indirectly indicate that a machine component near the sensor is heating up too much or that the immediate ambient temperature is rising. This can be an early warning of an impending machine standstill.

In addition to the temperature values and the voltage supply, the measured distance and frequency values are available for evaluation as a histogram. The statistical data can be reset at any time so that the statistics in the process are not distorted during sensor commissioning or replacement. Via the IO-Link interface, every system manufacturer can read out the data for their histogram evaluation intuitively and as required. There is also no need for laborious conversion of units, as the sensor already processes this internally and outputs it in the desired unit.

Most of this diagnostic data is also available for the Baumer ultrasonic sensors'UR18' and 'U500'.