Feature: Industrial electronics


ability to establish and manage multiple networks using a single physical device, mirror ports to monitor traffic, daisy-chain switches for local network expansion, secure network traffic, and ruggedise network components. To manage several networks in a single


Choosing the right Ethernet switch for rugged embedded computers


By Martin Frederiksen, Managing Director, Recab UK C


onnectivity is ubiquitous in industrial settings, and now it is increasingly used in non-commercial applications, too, ranging from on-board


entertainment on trains, to video transmission from military drones. In all of them, Ethernet switches play a crucial role. As the world becomes more


interconnected, the number of devices increases every day. Research firm McKinsey states that 127 new devices are connected every second; so, by the time you reach the end of this article, around 38,100 new devices would have been connected. Tese figures are even more significant if we count the local area networks (LANs) consisting of connected, critical embedded systems in sectors such as industrial, offshore, military and defence, rail and others. Switches are central to the performance


of networked architectures, allowing data to be relayed between connected computers and devices, and trafficked out to a larger


Research firm McKinsey states that 127 new devices are connected every second


network via protocols such as Ethernet. Protecting these switches is especially important for critical applications used in harsh environments, on-vehicle networks, both discrete and process manufacturing applications, and more. Ruggedisation is essential in demanding


environments, protecting the Ethernet switches to a high degree. Nevertheless, before considering ruggedisation, a look at the role of switches and network requirements is necessary.


Network technology features For network-based applications, there are several key requirements, including the


34 December/January 2021 www.electronicsworld.co.uk


device, it is possible to create a virtual LAN (VLAN) that groups networked devices under a separate Internet protocol (IP), based on needs and requirements. Different types of VLANs can be formed to meet application requirements, such as a port- based VLAN, to allow several IP networks and subnets to exist on the same switched network, or MAC-based, where specific MAC addresses are associated with each VLAN. Mirroring copies of sent and received


data packets to another port or VLAN, supporting the duplication of traffic from one port to another, is used for local and remote monitoring purposes and is vital for any application that analyses network traffic, such as for intrusion detection, event validation or traffic monitoring. Daisy-chaining Ethernet switches is


a physical connection scheme in which multiple switches are wired together in a sequence or ring. Tis is an efficient and simple expansion method when more nodes are needed at different points along the network. However, it is not an option for a network with nodes scattered over a large geographic region.


Security Security is a far more complex area, but a vital one for critical applications. Tere are two types of network security: virtual, primarily from soſtware systems and data encryption, and physical, where components play a role in maintaining data integrity. Intruder detection systems are one


example of network virtual security. Such a system detects a potential security breach and logs information about it. It can also sound an alert on the console or through its serial port, allowing technicians and IT teams to quickly act on the issue. Tis is all complemented by the network’s encryption standards. SNMPv3, for instance, is an encryption standard that allows simple


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