Today, most sensors and actuators are already equipped with microprocessors that are used to control indication, parameterization, and store configuration data. The next step is to overcome the bottleneck of the binary standard interface and make additional functions centrally accessible for the automation system.
For this reason, many well known manufacturers from the field of automation have come together and devel- oped a fieldbus-independent communication interface for sensors and actuators known as IO-Link. Compatibility with existing technologies was the primary objective during development in order to guarantee investment protection.
What is IO-Link?
IO-Link is based on a point-to-point connection between the sensor/actuator and an interface module. Previously, the binary connection was only designed for transferring switching information, but IO-Link now allows two bytes to be transferred normally in a 2 ms cycle via a combined switching status and data channel. Other information can be exchanged in addition to the process values, such as parameters or diagnostics messages. This enables communication with sensors and actuators down to the “last meter” to be established for universal communication.
IO-Link does not require any special wiring. The sensors and actuators can continue to be connected using the proven, unshielded and attractively priced industrial three core cables. The operating modes available for selection are the standard switch mode and the
IO-Link users benefit from reduced machine costs, efficient processes and improved machine availability. Turck provides one of the most comprehensive IO-Link portfolios worldwide, from a variety of sensors, cables and active IO-Link junction boxes to interfaces for various idustrial fieldbus protocols, including Turck Multiprotocol Ethernet products.
Reduced Machine Costs
• Reduced inventory due to intelligent multi-purpose devices
• Only one I/O module and one inexpensive standard cable required
• Reduced I/O footprint possible
• Displays and switches no longer required on devices
• Reduced engineering and assembly costs and automatic documentation of device parameters during the engineering phase
Engineering Tool Integration
Standardized interfaces (DTM/ IODD) implement seamless integration into engineering tools. Furthermore, integration into standalone tools such as Asset management or configuration tools is also made available. Connection into enterprise level tools is accomplished using standard Ethernet mechanisms.
Integrated device identification ensures that the correct device has been installed in the case of component replacements. As each device contains detailed information regarding the manufacturer, component replacement can be safely handled automatically.
IO-Link uses the same standard unshielded 3-core cables with standardized pinning as conventional I/O. This eliminates problems with complex devices which have no pinning standards and often multipole connectors.
• Extensive parameterization options for just in time parameter changes to devices
• Efficient processes requiring different parameter sets for switching thresholds, gain, sensitivity and so forth due to differing production conditions
• Faster tool change operations
IO-Link allows connection to most major fieldbuses, as well as Industrial Ethernet. Turck offers solutions for the full range, including master modules for its modular and block I/O systems featuring Multiprotocol Ethernet, which work seamlessly with PROFINET, EtherNet/IP and Modbus TCP in a single device.
All IO-Link devices allow param- eter changes and diagnostic evaluation within the engineering system or separate tools. Devices can now be mounted in the machine where they make sense for the application, not in inconvenient areas that disrupt work flow in order to allow access to display or switches.
Allow the integration of standard 24 VDC devices into automation systems via IO-Link with Turck I/O hubs. Variants for inputs, outputs and a version with configurable digital I/O are currently available.
Improved Machine Availability
• Comprehensive status information and diagnostic capabilities in the plant lead to drastically reduced machine downtime
• Enhanced information enables cost saving mechanisms such as predictive maintenance or asset management to be easily implemented
• Device replacement without manual intervention to parameterize the new unit alleviates the need for qualified personnel
Turck: Your Value Added IO-Link Solution Partner
Many manufacturers offer IO-Link products, which can make it difficult to find the most suitable partner for your needs. Turck offers a wide variety of IO-Link solutions - from sensors through programmable fieldbus and Ethernet gateways - but also provides a deep application knowledge, as the following example shows.
Many applications require that parts of a machine are changed to accommodate different phases in the production cycle. This necessitates providing manifold connections between the main (fixed) part of a machine and the exchangeable part. The two elements of the machine must then be linked mechanically and electrically to provide power, pneumatics and I/O signals to enable data exchange within the machine.
The electrical connections require large multi-pin connectors and multicore cables to achieve this end. This complexity has a price: the connections regularly cause problems and are expensive to buy and maintain. The fact that the connections also require a high degree of accuracy regarding the mechanical alignment between machine components further increases machine costs.
Another difficulty with this arrangement involves distinguishing between several variants of an exchangeable part. If this is necessary, further I/Os are required, both in the I/O system and on the machine. This not only increases costs, but also the complexity and sizing of the connectors between machine parts.
Value Added IO-Link Solution
Turck inductive couplers are capable of transferring both data and power over an air gap to resolve the previously mentioned problems. The contactless couplers eliminate the need for other mechanical connectors or costly slip rings, which are liable to wear.
Additionally, all Turck IO-Link devices are capable of allocating a so-called “Application Specific Tag” (part of the IO-Link specification), which fulfills the requirement of identifying changeable parts without incurring additional costs. Furthermore, this built-in mechanism allows the use of alpha-numeric information, making it likely that existing identification codes can be reused.