Optimizing industry 4.0 communication architectures using multi-protocol I/O hubs and converters
with hardware considerations, such as physical, data link, and network connections. Data addressing is the focus of the next three layers, which include the transport, session, and presentation processes. The seventh level of the model is the application layer, which provides the interface between the user and the network. Protocols like Modbus and PROFINET reside in this layer. The OSI model is more loosely related to other protocols like EtherNet/IP. In the case of EtherNet/IP, the application layer includes processes like web access (HTTP), e-mail (SMTP), file transfers (FTP), etc. The three Host layers implement the Transmission Control Protocol/Internet Protocol (TCP/IP) processes for establishing sessions, making error corrections, etc. The Media layers include the physical 10 Base-T connection and the implementation of the Ethernet data link and network connections (Figure 1). Where does IO-Link fit in? IO-Link is a single-drop digital communication interface (SDCI) for small sensors, actuators, and similar devices. It extends bidirectional communications down to individual devices on the
factory floor. It’s specified in IEC 61131-9 and is designed to be compatible with industrial network architectures based on Modbus, PROFIBUS, EtherNet/IP, etc. IO-Link uses a Master device to connect IO-Link devices to higher-level protocols like Modbus
programmable logic controllers (PLCs), human-machine interfaces (HMIs), a cloud data service (CDS), and so on. At the lowest level, IO-Link uses Hubs to aggregate multiple devices and feed the data up to a Master device. In addition, an analog voltage to the IO-Link Converter can be used to add analog sensors to the IO-Link network (Figure 2).
that provide connections to data-consuming devices like
Figure 1: How EtherNet/IP relates to the OSI seven-layer model.
6
Powered by FlippingBook