Industrial Ethernet (IE) is the use ofEthernet in an industrial environment with protocols that provide determinism and real-time control.[1] Protocols for industrial Ethernet includeEtherCAT,EtherNet/IP,PROFINET,POWERLINK,SERCOS III,CC-Link IE, andModbus TCP.[1][2] Many industrial Ethernet protocols use a modifiedmedia access control (MAC) layer to provide low latency and determinism.[1] Some microprocessors provide industrial Ethernet support.
Industrial Ethernet can also refer to the use of standard Ethernet protocols with rugged connectors and extended temperature switches in anindustrial environment, forautomation orprocess control. Components used in plant process areas must be designed to work in harsh environments of temperature extremes, humidity, and vibration that exceed the ranges forinformation technology equipment intended for installation in controlled environments. The use offiber-optic Ethernet variants reduces the problems of electrical noise and provides electrical isolation.
Some industrial networks emphasized deterministic delivery of transmitted data, whereas Ethernet usedcollision detection which made transport time for individual data packets difficult to estimate with increasing network traffic. Typically, industrial uses of Ethernet employ full-duplex standards and other methods so that collisions do not unacceptably influence transmission times.
Industrial use requires consideration of the environment in which the equipment must operate.Factory equipment must tolerate a wider range of temperature, vibration, physical contamination and electrical noise than equipment installed in dedicated information-technologywiring closets. Since critical process control may rely on an Ethernet link, the economic cost of interruptions may be high andhigh availability is therefore an essential criterion. Industrial Ethernet networks must interoperate with both current and legacy systems, and must provide predictable performance and maintainability. In addition to physical compatibility and low-level transport protocols, a practical industrial Ethernet system must also provide interoperability of higher levels of theOSI model. An industrial network must provide security both from intrusions from outside the plant, and inadvertent or unauthorized use within the plant.[3]
When an industrial network must connect to an office network or external networks, a firewall system can be inserted to control exchange of data between the networks. This network separation preserves the performance and reliability of the industrial network.
Industrial environments are often much harsher, often subject to oil sprays, water sprays, and physical vibrations, so often industrial Ethernet requires a more rugged and watertight connector on one or both ends of theCat 5 orCat 6 cable, such asM12 connectors or M8 connectors, rather than the8P8C connectors commonly used in homes and businesses.[4][5]
Programmable logic controllers (PLCs) communicate using one of several possible open or proprietary protocols, such asEtherNet/IP,EtherCAT,Modbus,Sinec H1,Profibus,CANopen,DeviceNet orFOUNDATION Fieldbus. The idea to use standard Ethernet makes these systems moreinteroperable.
Some of the advantages over other types of industrial network include:
Difficulties of using industrial Ethernet include:
Ethernet family oflocal area network technologies | |
|---|---|
| Speeds | |
| General | |
| Organizations | |
| Media | |
| Historic | |
| Applications | |
| Transceivers | |
| Interfaces | |
