For applications in harsh environments, commercial-grade PoE switches are insufficient to withstand certain extreme conditions. As such, users turn to industrial PoE switches.
In networking, PoE switches
transmit data from one device to another as well as supply power to the devices
, including IP cameras, over the Ethernet cable. However, for applications in harsh environments, commercial-grade PoE switches are insufficient to withstand certain extreme conditions. As such, users turn to industrial-grade PoE switches, which we examine in detail in this article.
What are industrial PoE switches?
Industrial PoE switches are also referred to as “hardened” or “ruggedized” PoE switches. Contrary to commercial-grade PoE switches that are often for office and indoor environments, industrial PoE switches are, as their name suggests, ideal for certain harsh, rugged environments. “The main reason for using industrial-grade PoE switches is to resist extreme fluctuations in temperature, dirt and moisture,” said James Hsiung, Application Engineer at Antaira Technologies.
“Normally, industrial PoE switches are needed in harsh environments with wide operating temperature and when power/network redundancy or specific certificates are requested,” said Winston Chien, PM Assistant Manager at Korenix.
“When the applications are required to be installed in harsh environments, we will suggest industrial-grade solutions, not only because of functionality, but also because the weather conditions and the prevention of electromagnetic interference (EMI) and electromagnetic susceptibility (EMS) need to be considered to keep solutions working perfectly, for instance traffic intersection monitoring,” said Molly Chu, Product Marketing Engineer at EtherWAN Systems.
According to Uwai Chen, VP of Engineering at Konten Networks, the following are some of the use scenarios in which industrial PoE switches can be useful:
- Wayside control
- In-vehicle: Bus
- In-vehicle: Self-driving truck
- Automated guided vehicle
- Tunnel monitoring
- Rolling stock
- Campus surveillance
- Roadside surveillance
What features should industrial PoE switches have?
Since they are installed in harsh environments where conditions are extreme and resources are limited, industrial PoE switches should have a set of features that overcome these condition.
“First of all, the switch should have operating temperature of up to 75°C; pass free fall, vibration and shock test; use a fan-less design; have dual power input for redundancy; are available with relay contact alarm; cope with extensive EMI/RFI phenomenon; and have housing with certain IP graded protection,” said Vince Yu, Project Manager at Lantech.
“As soon as you begin to define industrial-grade PoE switches, you have to take into account its ability to operate over a broad temperature range. As the temperature gets hot, for example, the laws of physics work against us when providing power to a video camera. Industrial PoE switches should feature fan-less design which operates better in dusty or harsh environments; should have din-rail functionality; and redundant power input to ensure the ongoing functionality of the device,” said Iain Deuchars, GM of ComNet.
The switch should have anti-explosion features as well. “There are specialized industrial switches that can operate in environments where there is a combustible atmosphere. Applications such as oil, gas, or high dust areas require equipment with explosion-proof ratings. This means that the equipment doesn’t generate a spark that could ignite the gas, or is placed inside an enclosure that prevents an explosion caused by the equipment to get outside the container,” said Bob Mesnik, President of Kintronics.
According to Chien, industrial PoE switches should also have other smart management features including:
- Power budget warning level – To ensure switch is working properly.
- PD status detection – to automatically determine which power classification, 802.af/at/bt, that the PD power source needs and then to check PD operating status regularly.
- PoE schedule – To activate PoE in specific period.
How do industrial PoE switches compare with commercial ones?
Since industrial PoE switches have different feature sets and are used in different applications than commercial PoE switches, a comparison between them is warranted.
“The simple way to describe this is: any unconditioned environment. Ethernet switches that we refer to as more commercial in nature require a conditioned environment. For conditions outside of that, the application requires industrial-grade switches where temperature is not a factor in functionality — whether it’s extreme heat or cold,” Deuchars said.
According to Sanjay Kumar, Chairman of Railway Recruitment Board at Indian Railways, the following are some of the differences between the two:
- The environment and other specifications of industrial PoE switch (such as -40°C to 75°C temperature range, shock, vibration and immunity) exceed harsh and industrial operating environment. Commercial grade has a temperature range of 0 to 40°C.
- Commercial switch power supply design is basically on a single supply basis, while industrial switch power supplies have generally dual/redundant power supply backups.
- Industrial PoE switches generally use a fan-less enclosure for heat dissipation, while commercial switches are fan-distributed type.
Further, commercial PoE switches typically are placed on racks. This is not the same for industrial ones. Chu of EtherWAN said: “When industrial-grade switches are installed in a harsh environment, space will be another consideration. Thus commonly we will see that industrial-grade PoE switches are designed with a DIN-rail type, due to more concern about space.”
What are some certifications that industrial PoE switches should have?
To prove that the industrial PoE switch is suitable for a particular vertical application, it should be certified for that application so that the end user can get the product that their project requires. These may include:
- IEC 61850-3: Defines the general requirements, mainly regarding construction, design and environmental conditions, for utility communication and automation IEDs (intelligent electronic devices) and systems in power plant and substation environments.
- EN 50155: An international standard covering electronic equipment used on rolling stock for railway applications. The standard covers aspects of this electronic equipment, including temperature, humidity, shock, vibration, and other parameters.
- EN 50121-4: This European Standard applies to signaling and telecommunication apparatus that is installed inside the railway environment.
Certification by the National Electrical Manufacturers Association can also help prove the industrial PoE switch is suitable for certain applications. “For example, for a surveillance system installed in an intersection in the U.S., NEMA TS2 helps to ensure the system integrity when installing in the traffic cabinet. Except for local power system compatibility, the video should constantly transmit the recorded footage back to the administrator through the PoE switch,” Chu said.
How secure are industrial PoE switches?
Being networked devices, industrial PoE switches are subject to the same cyber threats as any other equipment on the network. A security breach may cause production or operations to shut down, costing the end user significantly. Security features, then, become important for industrial PoE switches. “Indeed, this is a hot topic. For industrial applications, the end user are normally coming from the government, so how to protect these data is key, as some may consist of important video from public transportation and authorities,” Yu said.
According to Konten’s Chen, there are several protocols that industrial PoE switches can follow to increase security. These include:
- IEEE 802.1X: Part of the IEEE 802.1 group of networking protocols, providing an authentication mechanism to devices wishing to attach to a LAN or WLAN.
- RADIUS: Remote Authentication Dial-In User Service (RADIUS) is a networking protocol that provides centralized authentication, authorization and accounting management for users who connect and use a network service.
- TACACS+: Terminal Access Controller Access-Control System Plus can encrypt the full content of each packet. Moreover, it provides granular control.
- SSL: SSL or Secure Sockets Layer is the standard technology for keeping an internet connection secure and safeguarding any sensitive data that is being sent between two systems.
- SSH: Secure Shell is a software package that enables secure system administration and file transfers over insecure networks. It is used in nearly every data center and in every large enterprise.
“Konten Networks’ industrial Ethernet switches provide MAC-based network access control to restrict connected devices on the designated MAC Addresses,” Chen said. “Our industrial Ethernet switches provide both RADIUS server and TACACS+ server for authentication and authorization while user logs in. The username and password are managed by the server. The system will communicate with the server via encapsulated packets to prevent from attacks.”
Another standard to follow is the 802.1AE MACSec standard that protect data without compromising transmission speed. “Lantech is able to provide MACsec solution in order to offer integrity and confidentiality. When MACsec is in use, only authenticated peers are able to connect to the network, and all local attacks that ‘trick’ the switch to redirect network traffic to attacker machines do not work if MACsec is enabled,” Yu said.
Finally, it should also be noted that since industrial PoE switches are hardware devices placed on the outside, they should have certain physical security features to prevent theft or damage. “When we’re talking about industrial-grade PoE switches, the environments tend to be external to a secure building, so they’re often found outside, along a fence line, used in smart city applications or on the highway, so there are two considerations that must be in place: 1. the switch itself must be secured, and 2. the environment must be secure — for example, when used on the side of a highway, there should be a tamper-proof metal box protecting it,” Deuchars said.