15 Jul 2019
There are many different challenges in an industrial environment that standard commercial switches are not able to solve. Industrial Ethernet switches are designed for the harsh conditions and environments that are generally present in control networks, such as dust, dirt, vibrations, sweltering heat and freezing cold. Industrial switches don’t have the advantage of clean air-conditioned rooms and must be designed to operate in these extreme conditions.What's the difference?
In terms of functionality today, there is very little difference between an industrial switch and a commercial switch. Both are designed to pass IP traffic and provide a backbone for communication between the devices connected to them. There are two main areas where Industrial Switches differ, and these are:
- Type/availability of data
- Switch environment
Industrial networks have different priorities when compared to a commercial network, which means that industrial switches need to be more robust, not just to the environment, but also when it comes to the transmitting data. An industrial network must prioritise the delivery of data to ensure that the control network, for example a mine or factory, is able to operate safely and to minimise any downtime. This is achieved by using ring topologies such as MRP or RSTP to create a redundant network which can recover in as little as 50ms if there is a switch failure, or a cable is cut. There is no margin of error when even a short downtime can calculate to a million-dollar loss.
Industrial networks have much longer cycles than commercial networks, and therefore many legacy devices and protocols must be integrated into modern control networks. Managed industrial switches will often support fieldbus protocols such as Modbus or Ethernet/IP as the devices that are connected use these to communicate. Some switches will even have integrated serial ports that provided much needed support for this legacy equipment.DC powered
Another unique feature of an industrial switch is the fact that often, on site there will not be mains voltage, and the devices are powered via DC. A typical Industrial switch will operate between 12 – 48VDC, which can vary across the site meaning that Industrial devices must have a wide input range to cater for multiple power requirements. Industrial Ethernet switches also often have redundant power inputs. This allows the weakest link (the power supply) to have a redundancy via a backup power supply, ensuring maximum up time.Hazardous environments
Communication is required in some extremely harsh environments, such as a dirty, dusty underground mine, or a blistering hot open cut mine. An industrial switch must be able to not only withstand heat and dust, but do so without any moving parts, such as venting fans which reduce the MTBF of the device. MTBF (Mean Time Between Failures) is used to calculate the expected lifetime of a device. Industrial switches are built using components that can withstand temperatures ranging from -40 to +85˚C and are designed to last a lot longer than commercial switches, usually with MTBF figures calculated well over 10+ years.
Many industrial sites have very specific standards that need to be met with relation to vibration, or dust and water protection. Many Industrial devices are tested and can operate in very high vibration environments, which is achieved by not using moving parts and having special locking connectors for cables, such as an M12 connector. IP rating is also important with some devices designed to withstand not only dust but also water. A device such as Hirschmann’s Octopus is rated at IP67, meaning a complete protection from dust and protection from full immersion in water for 30 mins. Some devices are also designed for marine use, to protect against rust and high humidity.
Although there are many factors that separate Industrial switches from commercial switches, the reality is that as things like IOT and Industry 4.0 become more popular and more industrial networks are connected to the internet, Industrial switches and commercial switches are coming closer in terms of software, management and cybersecurity, while continuing to differentiate themselves to meet the requirements of their environment.