A Testbed for Evaluating QoS of Different Classes of Industrial Ethernet Protocols Based on Raspberry Pi

Internet technologies are driving developments in networking technologies for mechatronic devices. In the plant and manufacturing automation domain, internet technologies support for example cloud-based data exchange and a seamless connection of the Enterprise Resource Planning (ERP) and Manufacturing Execution System (MES). The communication of sensor-actuator loops on the field level is tackled with fieldbus technologies. Fieldbuses were introduced to tackle requirements such as real-time, safety, reliability and low costs that could hardly be met with Ethernet-based communication. Therefore, a variety of proprietary fieldbuses exists for the communication at the field level. For data exchange between different fieldbuses or for data upstream to higher automation layers, gateways to process data with significant time delays are mandatory. To overcome the shortcomings of Ethernet on the field level different approaches were proposed, labeled as Industrial Ethernet or Real-Time Ethernet (RTE). With Ethernet-based communication technologies, a vertical and horizontal integration of data is supported. While in simple or homogeneous networks, the estimation of Quality of Service (QoS) via simulation or calculation is possible; In complex architectures with heterogeneous protocols, different network layers, switches and gateways measurements are required. In this approach, a testing environment is presented to analyze different Ethernet-based technologies implemented on the single board computer i.e. Raspberry Pi. Therefore, measures for software configuration and a methodic analysis workflow are presented. This is beneficial to estimate QoS in planned communication architectures including different Ethernet-based protocols and gateways after defining requirements, functions and test scenarios.