An application example to calculate the predictive maintenance date was implemented using the SIMATIC IOT2000 and Node-RED. The PLC (SIMATIC S7-300) captures the switching cycles from a pneumatic valve. SIMATIC NET as an OPC UA Server sends these values to the OPC UA Client, the SIMATIC IOT2000, which stores them into a web-based cloud NOSQL DB database. The application uses the following nodes, which were installed via SSH (existing network connection required):

1. npm install node-red-contrib-opcua
2. npm install node-red-contrib-ibm-watson-iot

The attached Node-RED flow was used to realize this:

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The Data analysis for the predictive maintenance date is calculated cloud-based through IBM's Platform as a Service (PaaS) Bluemix. The Function calculates the maintenance date for the pneumatic valve by linear prediction and notifies the operator of the system automatically by e-mail. With some slight modifications, this concept of a prototypical application is reusable for other components of a plant, for example conveyors. The system can be used for elevators and moving platforms as well, by replacing the switching cycles with operating hours. Furthermore, other mathematical methods, for example exponential smoothing could be used to predict the maintenance date as well.