Industrial Ethernet
Encyclopedia
Industrial Ethernet refers to the use of the Ethernet
family of computer network
technologies in an industrial
environment, for automation
and process control
. A number of techniques are used to adapt Ethernet for the needs of industrial processes, which require real time
behavior. By using standard Ethernet, automation systems from different manufacturers can be interconnected throughout a process plant. Industrial Ethernet takes advantage of the relatively larger marketplace for computer interconnections using Ethernet to reduce cost and improve performance of communications between industrial controllers.
IE components used in plant process areas must be designed to work in harsh environments of temperature extremes, humidity, and vibration that exceed the ranges for information technology
equipment intended for installation in controlled environments.
(Programmable logic controller) would communicate with a slave machine using one of several possible open or proprietary protocols, such as Modbus
, Sinec H1
, Profibus
, CANopen
, DeviceNet
or FOUNDATION Fieldbus
. However, interest increased to use Ethernet as the link-layer protocol, with one of the above protocols as the application-layer (as in the OSI model
).
Some of the advantages are:
Difficulties of using Industrial Ethernet include:
(Note the highly ambiguous name given the Ethernet version of DeviceNet. The "IP" in Ethernet/IP stands for Industrial Protocol.)
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
family of computer network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
technologies in an industrial
Industrial engineering
Industrial engineering is a branch of engineering dealing with the optimization of complex processes or systems. It is concerned with the development, improvement, implementation and evaluation of integrated systems of people, money, knowledge, information, equipment, energy, materials, analysis...
environment, for automation
Automation
Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. In the scope of industrialization, automation is a step beyond mechanization...
and process control
Process control
Process control is a statistics and engineering discipline that deals with architectures, mechanisms and algorithms for maintaining the output of a specific process within a desired range...
. A number of techniques are used to adapt Ethernet for the needs of industrial processes, which require real time
Real-time computing
In computer science, real-time computing , or reactive computing, is the study of hardware and software systems that are subject to a "real-time constraint"— e.g. operational deadlines from event to system response. Real-time programs must guarantee response within strict time constraints...
behavior. By using standard Ethernet, automation systems from different manufacturers can be interconnected throughout a process plant. Industrial Ethernet takes advantage of the relatively larger marketplace for computer interconnections using Ethernet to reduce cost and improve performance of communications between industrial controllers.
IE components used in plant process areas must be designed to work in harsh environments of temperature extremes, humidity, and vibration that exceed the ranges for information technology
Information technology
Information technology is the acquisition, processing, storage and dissemination of vocal, pictorial, textual and numerical information by a microelectronics-based combination of computing and telecommunications...
equipment intended for installation in controlled environments.
Advantages and difficulties
Until recently, a PLCProgrammable logic controller
A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...
(Programmable logic controller) would communicate with a slave machine using one of several possible open or proprietary protocols, such as Modbus
Modbus
Modbus is a serial communications protocol published by Modicon in 1979 for use with its programmable logic controllers . Simple and robust, it has since become one of the de facto standard communications protocols in the industry, and it is now amongst the most commonly available means of...
, Sinec H1
Sinec H1
Sinec H1 is an Ethernet-based protocol that provides the transport layer function. The protocol was developed by Siemens and is used mainly for control applications. It has large bandwidth and is well suited to the transmission of large volumes of data....
, Profibus
Profibus
PROFIBUS is a standard for field bus communication in automation technology and was first promoted in 1989 by BMBF...
, CANopen
CANopen
CANopen is a communication protocol and device profile specification for embedded systems used in automation. In terms of the OSI model, CANopen implements the layers above and including the network layer. The CANopen standard consists of an addressing scheme, several small communication protocols...
, DeviceNet
DeviceNet
DeviceNet is a network system used in the automation industry to interconnect control devices for data exchange. It uses Controller Area Network as the backbone technology and defines an application layer to cover a range of device profiles...
or FOUNDATION Fieldbus
FOUNDATION fieldbus
Foundation Fieldbus is an all-digital, serial, two-way communications system that serves as the base-level network in a plant or factory automation environment. It is an open architecture, developed and administered by the Fieldbus Foundation....
. However, interest increased to use Ethernet as the link-layer protocol, with one of the above protocols as the application-layer (as in the OSI model
OSI model
The Open Systems Interconnection model is a product of the Open Systems Interconnection effort at the International Organization for Standardization. It is a prescription of characterizing and standardizing the functions of a communications system in terms of abstraction layers. Similar...
).
Some of the advantages are:
- Increased speed, up from 9.6 kbit/s with RS-232RS-232In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...
to 1 Gbit/s with Gigabit EthernetGigabit EthernetGigabit Ethernet is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second , as defined by the IEEE 802.3-2008 standard. It came into use beginning in 1999, gradually supplanting Fast Ethernet in wired local networks where it performed...
over Cat5eCategory 5 cableCategory 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors...
/Cat6Category 6 cableCategory 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk...
cables or optical fiberOptical fiberAn optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of... - Increased distance
- Ability to use standard access pointWireless access pointIn computer networking, a wireless access point is a device that allows wireless devices to connect to a wired network using Wi-Fi, Bluetooth or related standards...
s, routers, switchesNetwork switchA network switch or switching hub is a computer networking device that connects network segments.The term commonly refers to a multi-port network bridge that processes and routes data at the data link layer of the OSI model...
, hubs, cableCableA cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
s and optical fiberOptical fiberAn optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
, which are immensely cheaper than the equivalent serial-port devices - Ability to have more than two nodes on link, which was possible with RS-485 but not with RS-232
- Peer-to-peer architectures may replace master-slave ones
- Better interoperability
Difficulties of using Industrial Ethernet include:
- Migrating existing systems to a new protocol (however, many adapters are available)
- Real-time uses may suffer for protocols using TCPTransmission Control ProtocolThe Transmission Control Protocol is one of the core protocols of the Internet Protocol Suite. TCP is one of the two original components of the suite, complementing the Internet Protocol , and therefore the entire suite is commonly referred to as TCP/IP...
(but some use UDPUser Datagram ProtocolThe User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
and layer 2 protocols for this reason) - Managing a whole TCP/IP stack is more complex than just receiving serial data
- The minimum Fast Ethernet frame size including inter-frame spacing is about 80 bytes, while typical industrial communication data sizes can be closer to 1-8 bytes. This often results in a data transmission efficiency of less than 5%, negating any advantages of the higher bitrate.
- On Gigabit Ethernet the minimum frame size is 512Bytes, reducing the typical efficiency to less than 1%.
- Some of the Industrial Ethernet protocols introduce modifications to the Ethernet protocol to improve efficiency.
Main protocols
| Serial | Ethernet | Protocol | Network | Standards | |
|---|---|---|---|---|---|
| Modbus Modbus Modbus is a serial communications protocol published by Modicon in 1979 for use with its programmable logic controllers . Simple and robust, it has since become one of the de facto standard communications protocols in the industry, and it is now amongst the most commonly available means of... -RTU |
Modbus Modbus Modbus is a serial communications protocol published by Modicon in 1979 for use with its programmable logic controllers . Simple and robust, it has since become one of the de facto standard communications protocols in the industry, and it is now amongst the most commonly available means of... -TCP |
TCP/IP | IEC 61158 and IEC 61784 | ||
| Profibus Profibus PROFIBUS is a standard for field bus communication in automation technology and was first promoted in 1989 by BMBF... |
PROFINET IO PROFINET IO PROFINET is the open industrial Ethernet standard of PROFIBUS & PROFINET International for automation. PROFINET uses TCP/IP and IT standards, and is, in effect, real-time Ethernet.... |
Isochronous real time protocol (IRT Isochronous Isochronous : From Greek iso, equal + chronos, time. It literally means regularly, or at equal time intervals. In general English language, it refers to something that occurs at a regular interval, of the same duration; as opposed to synchronous which refers to more than one thing happening at the... ), Real time protocol (RT), Real time over UDP User Datagram Protocol The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring... protocol (RTU) |
Switches Network switch A network switch or switching hub is a computer networking device that connects network segments.The term commonly refers to a multi-port network bridge that processes and routes data at the data link layer of the OSI model... , router and wireless Wireless Wireless telecommunications is the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few meters for television remote control, or as far as thousands or even millions of kilometers for deep-space radio communications... , from 100 Mbit/s up to 1 Gbit/s |
IEC 61158 and IEC 61784 | |
| DeviceNet DeviceNet DeviceNet is a network system used in the automation industry to interconnect control devices for data exchange. It uses Controller Area Network as the backbone technology and defines an application layer to cover a range of device profiles... (CIP); ControlNet ControlNet -Introduction:ControlNet is an open industrial network protocol for industrial automation applications, also known as a fieldbus. ControlNet was earlier supported by ControlNet International, but in 2008 support and management of ControlNet was transferred to ODVA, which now manages all protocols... (CIP) |
Ethernet/IP EtherNet/IP EtherNet/IP is a communications protocol developed by Rockwell Automation, managed by the Open DeviceNet Vendors Association and designed for use in process control and other industrial automation applications.... (CIP) |
TCP/IP; UDP/IP | Switches Network switch A network switch or switching hub is a computer networking device that connects network segments.The term commonly refers to a multi-port network bridge that processes and routes data at the data link layer of the OSI model... , router and wireless Wireless Wireless telecommunications is the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few meters for television remote control, or as far as thousands or even millions of kilometers for deep-space radio communications... , from 100 Mbit/s up to 1 Gbit/s |
IEC 61158 and IEC 61784; ODVA Ethernet/IP standard | |
| Foundation Fieldbus H1 | Foundation Fieldbus High Speed Ethernet (HSE) | ||||
| CANopen CANopen CANopen is a communication protocol and device profile specification for embedded systems used in automation. In terms of the OSI model, CANopen implements the layers above and including the network layer. The CANopen standard consists of an addressing scheme, several small communication protocols... |
Ethernet Powerlink Ethernet Powerlink Ethernet Powerlink is a deterministic real-time protocol for standard Ethernet. It is an open protocol managed by the Ethernet POWERLINK Standardization Group... |
Ethernet 100Mbit/s | IEC 61158, EPSG (Ethernet Powerlink Standardization Group) | ||
| CANopen CANopen CANopen is a communication protocol and device profile specification for embedded systems used in automation. In terms of the OSI model, CANopen implements the layers above and including the network layer. The CANopen standard consists of an addressing scheme, several small communication protocols... |
EtherCAT EtherCAT EtherCAT - Ethernet for Control Automation Technology - is an open high performance Ethernet-based fieldbus system. The development goal of EtherCAT was to apply Ethernet to automation applications which require short data update times with low communication jitter and low hardware costs.-... |
EtherCAT, EtherCAT/UDP | Ethernet 100Mbit/s | IEC 61158, IEC/PAS 62407, IEC 61784-3, ISO 15745-4 | |
| VARAN Varan is a kaiju that first appeared in Varan the Unbelievable . Physically, Varan resembles a giant reptile with skin membranes between his arms and legs, allowing him to glide much like a flying dragon or flying squirrel; he also has a horned head.... Versatile Automation Random Access Network |
VARAN, TCP/IP, Safety | Ethernet 100Mbit/s | VARAN-BUS USER GROUP - VNO | ||
| SERCOS I / II | SERCOS III SERCOS III sercos III is the third generation of the sercos interface, a globally standardized open digital interface for the communication between industrial controls, motion devices, and input/output devices . sercos III merges the hard real-time aspects of the sercos interface with Ethernet. It is based... |
Ethernet 100Mbit/s | IEC 61491, merged into IEC 61158 | ||
| CC-Link Industrial Networks CC-Link Industrial Networks CC-Link is an open industrial network that enables devices from numerous manufacturers to communicate. It is predominantly used in machine, cell or process control applications in manufacturing and production industries, but can also be used in facilities management, process control and building... |
CC-Link IE | SLMP, TCP/IP | Ethernet 1Gbit/s, 100Mbit/s, 10Mbit/s, |
CLPA (CC-Link Partner Association) | |
| FL-Net (OPCN-2) | UDP/IP | Ethernet 10Mbit/s | by JEMA (Japan Electrical Manufacturers' Association) |
(Note the highly ambiguous name given the Ethernet version of DeviceNet. The "IP" in Ethernet/IP stands for Industrial Protocol.)
See also
- Computer networkComputer networkA computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
- Distributed control systemDistributed control systemA distributed control system refers to a control system usually of a manufacturing system, process or any kind of dynamic system, in which the controller elements are not central in location but are distributed throughout the system with each component sub-system controlled by one or more...
- FieldbusFieldbusFieldbus is the name of a family of industrial computer network protocols used for real-time distributed control, now standardized as IEC 61158....
- Human-machine interfaceHuman-machine interfaceHuman-machine interface is the part of the machine that handles the Human-machine interaction- Overview :In complex systems, the human-machine interface is typically computerized. The term Human-computer interface refers to this kind of systems....
- ModbusModbusModbus is a serial communications protocol published by Modicon in 1979 for use with its programmable logic controllers . Simple and robust, it has since become one of the de facto standard communications protocols in the industry, and it is now amongst the most commonly available means of...
- Process controlProcess controlProcess control is a statistics and engineering discipline that deals with architectures, mechanisms and algorithms for maintaining the output of a specific process within a desired range...
- Programmable logic controllerProgrammable logic controllerA programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...
- SCADASCADASCADA generally refers to industrial control systems : computer systems that monitor and control industrial, infrastructure, or facility-based processes, as described below:...