by Paul Rudo on 04/10/12 at 6:54 pm
An industrial Ethernet network has a very different set of requirements and challenges from a standard “commercial-grade” or office network. While the information on an office network is certainly important, the cost of data being delayed or lost can be very high in an industrial environment. Consider this: a production line in a plant may produce one million dollars’ worth of product per shift. If the production line goes down, the cost of this downtime is more than $2,000 a minute. This is a powerful incentive to take all necessary steps to assure that the network remains up and running, and is one reason why you need industrial-grade equipment. Let’s look at how an industrial-grade Ethernet network differs from a commercial or office network.
Environmental conditions are the first key difference in an industrial environment. Commercial network equipment is designed to operate in a climate-controlled office or wiring closet, where temperature and humidity are at ideal levels. In an industrial environment, the temperature is rarely controlled, and extreme temperatures often exist. It can easily range from below zero, such as in oil fields in northern Canada, to 70° C or above in oil production facilities in desert areas. While Ethernet switches with fans are common in commercial installations, they are not common in industrial environments because the Mean Time between Failure (MTBF) of a fan motor is about 25,000 hours. In addition, fans draw dust and dirt into equipment, so this can be an issue in factories where more damaging particulates are in the air.
Shock and vibration can be present in an industrial setting, where equipment can be mounted on anything from a metal stamping machine to a robotic arm. Commercial-grade network products are not designed to withstand these severe conditions.
ElectroStatic Discharge (ESD) is another issue for industrial networks that is not typically a problem in commercial environments. Motors, conveyers and other devices build up static charges. When copper network cables conduct this energy to Ethernet switches, this can cause damage. A commercial-grade switch can be severely damaged by ESD (even rendered useless) while industrial devices are hardened to withstand both ESD and variations or surges in the power supply.
Electromagnetic Interference (EMI) is another issue for industrial Ethernet networks. EMI is generated by devices such as motor drives, which are common on most plant floors. EMI interferes with communications by disrupting the electrical properties of the device and the cables. Industrial Ethernet components utilize rugged components and metal enclosures, making them well suited to withstand EMI without failure.
The functionality and software in an industrial Ethernet switch must be “lean and mean,” and some of the features that are nice to have in an office environment – but unnecessary in an industrial environment – are omitted in favor of faster data transmission. Some industrial applications require extremely short “boot-up” times – the time from the moment power is applied until the device is operational. This is because network devices can be part of a tool or robot that is removed or installed as part of the manufacturing process, and excess boot time is simply another form of downtime.
Ease of configuration and repair is important, because most industrial networks do not have a 24×7 IT department for support. The network in industrial settings is often maintained by plant maintenance personnel, not IT staff. Industrial networks must maximize “uptime” and be very simple to troubleshoot and repair. While the phrase “plug-and-play” is often misused, devices that have some degree of self-configuration capability will positively affect productivity.
Redundancy and rugged construction combine to keep industrial Ethernet switches working, but any machine is subject to failure or damage at some point. It is important to build in ease-of-replacement features into industrial network devices. These include Dynamic Host Configuration Protocol (DHCP) to assign IP address, and Automatic Internet Group Management Protocol (Auto IGMP Snooping) to manage Multicast traffic and improve network performance. If a device can configure itself and doesn’t require an IT person to install and configure it, the Mean Time to Repair (MTTR) will be lower, resulting in maximum uptime and minimal lost production.
Industrial environments like factory floors and oil fields have harsh conditions that regular commercial-grade Ethernet switches could simply not withstand. Industrial-grade Ethernet switches are specially designed and built to handle these conditions and work properly on a constant basis, keeping the modern, “data driven” industrial processes of today working smoothly.
About The Author: Tony Oberkirch is a Marketing Analyst Red Lion Controls, a leading vendor of industrial Networking hardware.
Image Source: http://www.flickr.com/photos/frijole/991092035/