Free Newsletter
Register for our Free Newsletters
Advanced Composites
Amorphous Metal Structures
Analysis and Simulation
Asbestos and Substitutes
Associations, Research Organisations and Universities
Automation Equipment
Building Materials
Bulk Handling and Storage
CFCs and Substitutes
View All
Other Carouselweb publications
Carousel Web
Defense File
New Materials
Pro Health Zone
Pro Manufacturing Zone
Pro Security Zone
Web Lec
Pro Engineering Zone

New ABB wireless sensor takes machine control to the next level

ABB Limited (Group Headquarters) : 19 May, 2005  (New Product)
Utilising a new wireless protocol and power system developed by ABB, the wireless proximity switch eliminates the need for cabling in sensor applications, cutting the time and cost of installation by up to two-thirds.
To date, most machine control applications have used inductive proximity switches. Based on the electromagnetic induction principle, these sensors are designed to detect metal targets and are generally insensitive to the effects of dirt. A major drawback, however, is the cost and quantity of cabling needed to connect each sensor to a factory's control system. Commonly located on moving parts of machines, these types of sensors are prone to malfunction due cable damage caused by wear and tear.

With no need for cabling, ABB's wireless proximity switch overcomes these problems. Data is relayed from the switch to the machine control system using ABB's new WISA protocol, specifically designed for industrial applications. Wireless Interface for Sensors and Actuators links signals from sensors and actuators to an input module via radio antennas which then communicate sensor signals to the machine control system. The input module is capable of receiving signals from up to 120 switches at a time. These signals are then transmitted to the machine control system. Using ABB's FieldbusPlug solution, the input mode can also be connected into a fieldbus system using any of the major protocols such as Profibus, AS-I or DeviceNet.

Through the switch's full-duplex operation, radio signals can be simultaneously transmitted and received, ensuring rapid flow of data both to and from the switch. To protect against loss of signal, it can also simultaneously receive both strong and weak signals, even where a large interfering signal may exist at an adjacent frequency.

Added protection against signal deterioration is also afforded by the swapping of the transmission and reception antennas at the input module, this ensures that there is always a path for the signal.

For system diagnostic purposes, the switches also transmit anI'm alive message twice per second. Furthermore, because communication takes place in the license free 2.4GHz ISM band, there is no need to have the system authorized in individual countries, making it readily available for use worldwide.

To eliminate the need for power cables, ABB has also developed a system which uses an electromagnetic field created from an alternating current running through primary power loops. The wireless switch is equipped with small secondary coils that pick up energy from the magnetic field and transform it to electric power. This provides the wireless switch with a constant, uninterrupted supply of power, making it ideal for factory automation applications where machines need to be in constant use.

The wireless proximity switch consists of two parts: the sensor head and the communication module. Power supply, signal transmission and human-machine communication are provided by a single type of communication module. The first batch of proximity switches on the market is available in four different sensor head sizes and covers switching distances ranging from 1.5mm to 15mm. The switches are available in flush or non-flush mounted design, have an IP67 protection rating and can operate in environments ranging from -25oC to 55oC. The switches are also supplied with one type of power supply, primary loop cable, one radio antenna and an input module for communication with the machine controller.
Bookmark and Share
Home I Editor's Blog I News by Zone I News by Date I News by Category I Special Reports I Directory I Events I Advertise I Submit Your News I About Us I Guides
   © 2012
Netgains Logo