In the industrial automation field, each industrial device is networked and plays a very important role when it comes to the operation of the entire industrial system. This is unlike the average office application, in which the failure of Ethernet equipment might merely mean that a few PCs cannot send e-mail messages for a few minutes. In the industrial application, when an industrial device loses its connection to the network, the result could be a huge financial loss. When choosing Ethernet equipment to fulfill the requirements of industrial applications, and to ensure that your entire industrial system keeps running smoothly, you should keep the following points in mind:

• Higher reliability is essential for industrial applications
• Providing fast recovery capability and security helps ensure continuous operation
• Dynamic status reports that give the status of industrial equipment and devices can prevent system damages and losses
• Key management functions make it easy to master industrial Ethernet networks

Higher reliability is essential for industrial applications

A new industry has sprung up to provide Ethernet products that comply with the requirements of demanding industrial applications. To ensure essential reliability for industrial applications, users should demand Industrial Ethernet products that have with the following features:

• Redundant power inputs to prevent single power failure
• Ring topology support to provide redundant path backup
• Industrial Ethernet products built with components that are better quality and more reliable, ensuring a higher MTBF
• The ability to withstand extreme temperature conditions, such as from -40 to 75°C
• Industrial Ethernet products designed with a rugged high-strength case to keep out harmful substances.
• Industrial Ethernet products that comply with industrial regulatory conditions (CE, FCC, UL, etc.), and are designed to withstand shock, drop, and vibration conditions.

Providing fast recovery capability and security helps ensure continuous operation

The above list only gives the basic requirements for industrial applications. When considering industrial communications, reliability means more than just a strong casing and good endurance to extreme temperatures, but also involves more fault resilience functionality. In the office, a 3-minute communication failure could be passed off as a minor inconvenience, whereas in an industrial setting, the same 3 minutes could cause a tremendous loss in investment. With this in mind, the following self-recovery functions can provide the essential functionality needed to keep the network running continuously.

• Self recovery watch-dog to prevent random service interruptions
• Line-swap fast recovery that responds when devices change their port position, so that networked devices can keep communicating without facing several minutes of downtime

Another important consideration is that when industrial Ethernet equipment is used as part of an automation system, it is more often used to connect devices, as opposed to computer hosts. And since all automation systems incorporate sensitive devices that must be protected from unauthorized access, it is very important to have some type of authentication system set up to restrict access to authorized users.

• Isolate selected groups of devices to prevent unauthorized access

Dynamic status reports that give the status of industrial equipment and devices can prevent system damages and losses

Industrial Ethernet equipment that connects these devices must take responsibility for providing system maintainers with real-time alarm messages. Even when control engineers are out of the control room for an extended period of time, they can still be kept informed of the status of devices almost instantaneously when exceptions occur. Warning messages must be actively triggered by events. In consideration of these requirements, industrial network equipment must have features such as:

• Send out a warning message (e.g., by e-mail) when an exception is detected

• Provide signal outputs (e.g., digital output, relay contact) to warn engineers who are working in the field

Key management functions make it easy to master industrial Ethernet networks

• Identifying network segment integrity by sending a "ping" command
• Remote data scope analyzes local network behavior from a remote location
• Assigning IP addresses to connected devices
• Setting up mirroring ports for better online data monitoring

• SNMP support for easy network analysis
• OPC Server support for easy integration into your automation system

In conclusion, we not only need Ethernet equipment that has a hardened industrial design and that must work in demanding environments, but also equipment that comes with many useful management and monitoring functions. Such functions include a self recovery watch-dog, the ability to isolate selected groups of ports, and the automatic issuance of warning e-mail when an exception to regular network or device operation is detected. Additional functions that users should look for are the ability to send "Ping" commands to detect which network segment has problems, the ability to set up IP addresses of connected devices, and an implementation of mirroring ports to monitor true port activity.

In short, state of the art Industrial Ethernet products should provide:

• The ability to keep industrial automation systems running continuously
• Real-time alerts that provide the status of networked industrial devices
• The capability to easily master the integrity of the industrial network
• An industrial device oriented design