Využití MQTT pro průmyslové aplikace

Abstract

This thesis deals with the design and implementation of communication between Siemens S7-1500 series PLCs and devices with installed InfluxDB time series database system. The goal was to create an efficient way of collecting and transferring production data from the Siemens S7-1500 PLC to the database environment, with an emphasis on low latency, scalability and reliability of the transfer. The paper describes the library functions developed in the TIA Portal environment, including the use of the LMQTT\_Client library, which allows the implementation of an MQTT client directly on the PLC.

The proposed system uses serialization techniques and the sequential sending of individual values from a data block to specific MQTT toplets and sending data in JSON format. The solution includes the implementation of a controlled delay between messages to optimize PLC performance. Furthermore, integration with the InfluxDB database system was implemented for the permanent storage of historical data and its subsequent analysis. The stored data in InfluxDB is visualized using the Grafana platform, where each stored variable is displayed in a graph. The paper also includes a comparison of different approaches to data collection in an industrial environment and the implementation of a demonstration application for monitoring electricity consumption.