Feature: Components


Whether a switch is intended for on-track or rolling-stock use


determines the applicable regulatory standard. For rolling-stock switches like the NL30 and EPSM-10GX4, the requirement is the EN 50155 railway standard, which ensures that the switch is suitable for the temperature range, shock and vibration levels encountered in rolling-stock applications.


Military switches Military embedded systems are oſten tasked with data-intensive processes, such as capturing and processing data from images and video feeds on a military vehicle, for example. Tis data is processed in the field but is then transmitted back to a command centre, quickly, efficiently and securely to ensure that swiſt decisions and responses are coordinated. Because security is of utmost importance, military and


defence Ethernet switches should include native features to maximise protection of network data. Tese include port- level authentication, mirroring to support traffic monitoring, and mixed media or fibreoptic ports to protect against electromagnetic snooping. Te switches themselves are also required to be ruggedised, with


a wide operating temperature suitability and high shock resistance. Ruggedisation of switches to meet military standards requires


consideration such as PCB thickness, latching connectors and enclosures, all while considering size, weight and power (SWaP). An ideal switch that meets these strict criteria is the Aitech A661 small Ethernet switch (Figure 1), which comprises two 24-port Ethernet switch boards in a rugged enclosure, allowing for 48 ports with data rates of 10/100/1000Mbps. Tis switch can handle layer-two and -three routing and switching, it features port monitoring for non-invasive switch traffic, and uses 802.1X authentication for port-level security. Its robust enclosure is ingress-protected, designed with EMI and RFI in mind to block external intrusion. In fact, the A661 has successfully passed space-radiation tests and has been installed on the International Space Station. Te system’s power and input/output connections are ruggedised MIL-STL-38999 connectors for regulatory compliance and lasting performance. In addition to the A661, Aitech also offers a standalone managed


Ethernet switch/router, the A664, which is SWaP-optimised to make it an ideal option for military networks where size or weight is limited. Like the A661, the A664 is fully ruggedised to withstand harsh military environments, and also includes four multimode


optical fibre ports for fibre communications at distances to 550m where copper cabling is not viable. Te A664 can meet yet another critical requirement for


military networks – resiliency. Te switch offers improved network resiliency by featuring the Spanning Tree (xSTP) and virtual router redundancy (VRRP) protocols.


Marine switches Increasingly, offshore and marine applications are embracing connectivity as a way of reducing maintenance costs for remote systems or to use unmanned vehicles with lidar or sonar to produce topographic maps of subsea environments. Tese are just two examples, but, in both cases, data needs to be sent to a network of devices. Ethernet switches in marine environments must be adequately


ingress-protected to IP67 or higher, as well as operate effectively under low temperatures for long periods of time. In terms of network functionality, the Ethernet switch should ideally support many data paths, if intended to handle data from sonar or radar systems. With these considerations in mind, the new VX6940 6U


VPX Ethernet switch from Kontron is a suitable option for VPX platform applications. Tis is a layer-two/three switch designed for long-term applications. It features two front QSFP28 transceivers, which support to 100G optical or passive copper connections, and each with four 10GB or SFP+ ports. Kontron’s VX6940 switches are best suited to data-intensive


applications that require many data paths, such as naval sonar or radar systems, when coupled with Kontron ARM or X86 computing nodes.


Outside the box Far from being confined to IT environments, Ethernet switches are now present in demanding industrial environments across the globe. Of course, not every switch is suited to every potential environment, which is why it’s important to partner with an embedded expert who can recommend or design the right switch. As the IIoT and network connectivity extends to more


industries and applications, Ethernet switches will continue to perform a crucial role into the future. Although oſten overlooked, their importance cannot be overstated – nor can the importance of making the right choice.


Figure 2: NL30 Ethernet switch


www.electronicsworld.co.uk March 2021 35


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