Ethernet-based protocols are getting more and more important for Industry 4.0 and the Internet of Things. In this paper, we compare the features, package overhead, and performance of some of the most important protocols in this area. First, we present a general feature comparison of OPC UA, ROS, DDS, and MQTT, followed by a more detailed wire protocol evaluation, which gives an overview over the protocol overhead for establishing a connection and sending data. In the performance tests we evaluate open-source implementations of these protocols by measuring the round trip time of messages in different system states: idle, high CPU load, and high network load. The performance analysis concludes with a test measuring the round trip time for 500 nodes on the same host.

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Abstract-Modern manufacturing systems require a transformation from mass production towards mass customization. This results in a trend towards more agile production lines. It also demands a reduction of configuration times when building the production line as well as faster reconfiguration when adding new hardware and product variants to the manufacturing line. This paper introduces the concept of a device adapter that allows the device to be seamlessly plugged into the agile production systems. The device adapter wraps the device functionality and offers it as a service, hiding away the low-level process capability (skill) implementation and allowing to formally represent the production steps. Preliminary tests have been performed on an industrial demonstrator that simulates a real manufacturing process.