About Industrial Ethernet
The prevalence of Ethernet as a networking standard and the resulting low price and diversity of COTS Ethernet components have paved the way for industrial Ethernet applications in areas where fieldbuses were previously used.
While modern Ethernet implementations (Fast Ethernet, Gigabit Ethernet) offer great advantages over traditional fieldbuses when it comes to bandwidth or supported cable length, additional measures needed to be taken to ensure the real-time behavior and ruggedness necessary for many industrial applications. Current Ethernet-based industrial communication systems usually utilize Ethernet as the link layer with extensions of the common TCP/IP or UDP/IP or their own custom protocols on top. For instance, three different protocol levels are defined for Profinet depending on the reaction time requirements of the application. The slowest uses TCP/IP while Profinet's own Real-Time Protocol or the even faster Isochronous Real-Time Protocol are used for more time-critical systems. The competitor EtherNet/IP (Industrial Protocol) uses the regular TCP/IP and UDP/IP protocols as a foundation and adds CIP (Common Industrial Protocol) as an application layer for industrial automation applications. These solutions add crucial features while still enabling the use of standard Ethernet components (access points, switches, routers, cables, etc.) in the resulting system.
Industrial Ethernet applications often specify operation in harsh environments, e.g., the ability to withstand shock, vibration, humidity and extreme temperatures. MEN has answered the call for suitably rugged devices by utilizing conformally coated PCBs, no socketed components and fanless designs that require no cooling. Since the standard RJ45 Ethernet connectors do not always meet an application's requirements for ruggedness, most Ethernet-enabled MEN products are available with rugged M12 connectors as an alternative, offering protection up to IP67. MEN has developed rugged Ethernet interface boards based on standards like CompactPCI® (Serial), PMC, XMC and PC-MIP® and offers a wide selection of Ethernet switches in CompactPCI® (Serial) format and as stand-alone devices. The latter include particularly rugged models compliant with the strict requirements of EN 50155 and designed for mounting in standard 19-inch racks or on a DIN rail, making them perfectly suited for demanding industrial applications.
In addition to the typical fieldbus applications like industrial automation, Ethernet is becoming more and more popular in railway applications, commercial vehicles and ships. There, its bandwidth advantages over traditional fieldbuses make it ideal to transfer high quality video and audio content, e.g., for passenger information systems.