19-05-2012, 12:56 PM
Efficient Industrial Automation Using ZigBee Wireless Networks
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Abstract
In order to reduce the need of human work in the production of goods and services, many industries are going for automation. With the help of PLCs Hard-wired automation is already being implemented in many major production industries. But wired networks are costly and are not suitable in some environmental conditions. At the same time, the wireless standards being used so far are prone to interferences caused by RF noises coming from machinery, changes in the physical environment, etc. causing the packet delivery to fail. And also they use Star topology which is simple to deploy, maintain and expand, and has been in practice since long time. However, in industries if a link between a node and the base station fails, that node no longer participates in the application. So eventually application stops working. At present, the ZigBee wireless standard is being implemented in many industrial arenas because of its low cost and its mesh networking capabilities. ZigBee can be implemented with any existing network by just modifying the gateway and Modbus of existing system components.
1. Introduction
In this technical world everything is getting automated. In order to reduce man power and increase productivity, industries have automated machineries using hard-wired networks. Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. Regardless of specific application needs, industrial automation networks consist of PLCs (programmable logic controllers) that communicate with remote sensors to gather data regarding physical variables such as pressure, temperature, vibration, sound, and strain. When the application includes a control function, PLCs act on that data by issuing commands that or chest rate processes among such actuators as relays, motors, solenoids, and valves. The success of this automation depends on reliable communications between PLCs and sensors/actuators. The communication links have traditionally been hard-wired, with data transmitted over cable.
2. Disadvantages of Other networks
Despite its advantages, wired industrial networking has well known drawbacks. Data cabling represents a tremendous labor cost, in both initial runs and in reconfiguration. The cables themselves are unwelcome in many factory environments, where they can represent nuisances or safety hazards. And Cabling runs have severe length limits, leaving networks unable to address every remote sensors and actuators in such environments as oil fields and large scale plants. In the wired networks, wires have connectors and, connectors get broken over time, especially if they are plugged in frequently. The wires themselves get caught on things and get cut.
Wireless networking has always been a solution to these issues, with a primary requirement of preserving communications reliability. But in the other hand, there are many factors that affect wireless networks such as; RF noises coming from machinery, changes in the physical environment, etc. In the spectrum used for wireless communication there is even more interferences which can all change the wireless characteristics, causing packet delivery to fail.
Most wireless networks feature star topology, in which a base station manages communication with remote nodes in a point-to-multipoint fashion. This topology is simple to deploy, maintain and expand, and has been in practice since long time. However, in industries if a link between a node and the base station fails, that node no longer participates in the application. So eventually application stops working. It can be overcome by many methods but it just adds to the cost. In the other hand, ZigBee wireless standards with its mesh networking and per-hob and end-to-end retries and acknowledgements, turns the unreliable medium into a very reliable network.
3. ZigBee and its Features
ZigBee is a new wireless technology developed by the ZigBee Alliance to overcome the limitations of BLUETOOTH and Wi-Fi. The ZigBee protocol is a worldwide open standard providing low-power, wireless connectivity for a wide range of applications that perform monitoring or control functions. The standard overcomes the traditional
Limitations of low-power, wireless network solutions—such as short range, restricted coverage and vulnerability to node and radio link failures.
ZigBee enhances the functionality ofIEEE802.15.4 by providing flexible, extendable network topologies with integrated setup and routing intelligence to facilitate easy installation and high resilience to failure. ZigBee networks also incorporate listen before-talk and rigorous security measures that enable them to co-exist with other wireless technologies, such as Bluetooth and Wi-Fi, in the same operating environment.
The features of this wireless connectivity standard allow ZigBee-based products to be installed easily and cost effectively, and its built-in intelligence and flexibility allow networks to be easily adapted to changing needs by adding, removing or moving network devices. The protocol is designed to allow devices to appear and disappear from the network, so devices can be put into a power saving mode when not active. This means that many devices in a ZigBee network can be battery powered, making them self-contained and reducing installation costs. ZigBee includes measures to avoid interference between radio communications—such as its ability to automatically select the best frequency channel at initialization. Where possible, it will also adapt to a changing RF environment by automatically selecting another channel if the current channel proves problematic.
4. Applications of ZigBee
ZigBee Technology can be used on everything you can imagine for wireless sensor nodes or in general short range communications. Today, organizations use ZigBee to effectively deliver solutions for a variety of areas including consumer electronic device control, energy management and efficiency, home and commercial building automation as well as industrial plant management.
Industrial & commercial: In Industries ZigBee technology can be used to automate monitoring and controlling of various physical values.
Personal health care: ZigBee is used for Chronic Disease monitoring, continuous patient monitoring, Personalised wellness monitoring, Senior activity monitoring etc. Various ZigBee products such as Glucose Meter, Pulse oxi-meter, Electrocardiograph and Social Alarm devices are also available.
Home/Hotel automation: centralized HVAC management allows us to make sure empty rooms are not cooled. Lighting network can be integrated with and/or be used by other building control solutions
5. Industrial Automation
ZigBee has got lots of applications as discussed above but in this paper we are going to discuss how ZigBee can be used for Industrial Automation. The main advantages of ZigBee standard such as low cost, Low power consumption and mesh topology plays a vital role in industrial automation. Because of its low cost, it encourages adoption throughout industrial settings, extending benefits to even the simplest nodes. It’s more reliable because of mesh topology.
ZigBee network consists of controllers, sensors and actuators working in concert to monitor and control machines.
Controllers can be Central or Distributed PLCs.
ZigBee sensors can monitor temperature, Acoustic, Pressure, Strain, Vibration, etc.
Actuators: Valves, Motors, Solenoids, Relays
6. a) Implementing ZigBee in Pre-Exiting Networks
In an already existing wired installations, as many wireless installations involves the replacement of wiring in an established environment, ZigBee cost-effectiveness requires that it interface with the existing equipment and support existing network protocols.
[attachment=22442]
Abstract
In order to reduce the need of human work in the production of goods and services, many industries are going for automation. With the help of PLCs Hard-wired automation is already being implemented in many major production industries. But wired networks are costly and are not suitable in some environmental conditions. At the same time, the wireless standards being used so far are prone to interferences caused by RF noises coming from machinery, changes in the physical environment, etc. causing the packet delivery to fail. And also they use Star topology which is simple to deploy, maintain and expand, and has been in practice since long time. However, in industries if a link between a node and the base station fails, that node no longer participates in the application. So eventually application stops working. At present, the ZigBee wireless standard is being implemented in many industrial arenas because of its low cost and its mesh networking capabilities. ZigBee can be implemented with any existing network by just modifying the gateway and Modbus of existing system components.
1. Introduction
In this technical world everything is getting automated. In order to reduce man power and increase productivity, industries have automated machineries using hard-wired networks. Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. Regardless of specific application needs, industrial automation networks consist of PLCs (programmable logic controllers) that communicate with remote sensors to gather data regarding physical variables such as pressure, temperature, vibration, sound, and strain. When the application includes a control function, PLCs act on that data by issuing commands that or chest rate processes among such actuators as relays, motors, solenoids, and valves. The success of this automation depends on reliable communications between PLCs and sensors/actuators. The communication links have traditionally been hard-wired, with data transmitted over cable.
2. Disadvantages of Other networks
Despite its advantages, wired industrial networking has well known drawbacks. Data cabling represents a tremendous labor cost, in both initial runs and in reconfiguration. The cables themselves are unwelcome in many factory environments, where they can represent nuisances or safety hazards. And Cabling runs have severe length limits, leaving networks unable to address every remote sensors and actuators in such environments as oil fields and large scale plants. In the wired networks, wires have connectors and, connectors get broken over time, especially if they are plugged in frequently. The wires themselves get caught on things and get cut.
Wireless networking has always been a solution to these issues, with a primary requirement of preserving communications reliability. But in the other hand, there are many factors that affect wireless networks such as; RF noises coming from machinery, changes in the physical environment, etc. In the spectrum used for wireless communication there is even more interferences which can all change the wireless characteristics, causing packet delivery to fail.
Most wireless networks feature star topology, in which a base station manages communication with remote nodes in a point-to-multipoint fashion. This topology is simple to deploy, maintain and expand, and has been in practice since long time. However, in industries if a link between a node and the base station fails, that node no longer participates in the application. So eventually application stops working. It can be overcome by many methods but it just adds to the cost. In the other hand, ZigBee wireless standards with its mesh networking and per-hob and end-to-end retries and acknowledgements, turns the unreliable medium into a very reliable network.
3. ZigBee and its Features
ZigBee is a new wireless technology developed by the ZigBee Alliance to overcome the limitations of BLUETOOTH and Wi-Fi. The ZigBee protocol is a worldwide open standard providing low-power, wireless connectivity for a wide range of applications that perform monitoring or control functions. The standard overcomes the traditional
Limitations of low-power, wireless network solutions—such as short range, restricted coverage and vulnerability to node and radio link failures.
ZigBee enhances the functionality ofIEEE802.15.4 by providing flexible, extendable network topologies with integrated setup and routing intelligence to facilitate easy installation and high resilience to failure. ZigBee networks also incorporate listen before-talk and rigorous security measures that enable them to co-exist with other wireless technologies, such as Bluetooth and Wi-Fi, in the same operating environment.
The features of this wireless connectivity standard allow ZigBee-based products to be installed easily and cost effectively, and its built-in intelligence and flexibility allow networks to be easily adapted to changing needs by adding, removing or moving network devices. The protocol is designed to allow devices to appear and disappear from the network, so devices can be put into a power saving mode when not active. This means that many devices in a ZigBee network can be battery powered, making them self-contained and reducing installation costs. ZigBee includes measures to avoid interference between radio communications—such as its ability to automatically select the best frequency channel at initialization. Where possible, it will also adapt to a changing RF environment by automatically selecting another channel if the current channel proves problematic.
4. Applications of ZigBee
ZigBee Technology can be used on everything you can imagine for wireless sensor nodes or in general short range communications. Today, organizations use ZigBee to effectively deliver solutions for a variety of areas including consumer electronic device control, energy management and efficiency, home and commercial building automation as well as industrial plant management.
Industrial & commercial: In Industries ZigBee technology can be used to automate monitoring and controlling of various physical values.
Personal health care: ZigBee is used for Chronic Disease monitoring, continuous patient monitoring, Personalised wellness monitoring, Senior activity monitoring etc. Various ZigBee products such as Glucose Meter, Pulse oxi-meter, Electrocardiograph and Social Alarm devices are also available.
Home/Hotel automation: centralized HVAC management allows us to make sure empty rooms are not cooled. Lighting network can be integrated with and/or be used by other building control solutions
5. Industrial Automation
ZigBee has got lots of applications as discussed above but in this paper we are going to discuss how ZigBee can be used for Industrial Automation. The main advantages of ZigBee standard such as low cost, Low power consumption and mesh topology plays a vital role in industrial automation. Because of its low cost, it encourages adoption throughout industrial settings, extending benefits to even the simplest nodes. It’s more reliable because of mesh topology.
ZigBee network consists of controllers, sensors and actuators working in concert to monitor and control machines.
Controllers can be Central or Distributed PLCs.
ZigBee sensors can monitor temperature, Acoustic, Pressure, Strain, Vibration, etc.
Actuators: Valves, Motors, Solenoids, Relays
6. a) Implementing ZigBee in Pre-Exiting Networks
In an already existing wired installations, as many wireless installations involves the replacement of wiring in an established environment, ZigBee cost-effectiveness requires that it interface with the existing equipment and support existing network protocols.