Using IO-Link allows you to get as much data as possible from only three wires. IO-Link communicates four types of data: device data, event data, value status, and process data. Value status data and process data are constantly sent together at a known rate that is documented in each device’s manual and/or data sheet. Device and event data stores your device parameters and allow for the ultimate flexibility of IO-Link devices. Since the IO Device Description (IODD) files contain each device’s full set of parameters, using them saves you from the need to regularly refer to the manual.
Commissioning IO-Link devices
When first using an IO-Link device, the standard process data will be displayed. To maximize the functionality of the device, parameters can be accessed and, in some cases, changed. The available parameters for any IO-Link device are located in at least two places: the device’s manual and the device’s IODD file. The manual will display the required hexadecimal-based index and sub-index addresses to point your controller’s logic, which will allow the user to change/monitor parameters of the device during operation. This is great for utilizing one or two parameters.
However, some devices require a large number of parameter adjustments to optimize each device per application. Using IODD files to commission devices can be faster and make it easier to select and change parameters, because all available parameters are included in the XML based file. Certain masters and controllers have the ability to store these IODD files, further improving the integration process. Once the IODD files are stored and the device is plugged into an IO-Link port, you can choose, change, and monitor every parameter possible.
Where can I find IODD files?
The IO-Link consortium requires all IO-Link device manufacturers to produce and post the files to the IODD finder located on io-link.com. Most IO-Link device manufacturers also provide a link to the IODD file on the product’s web page as well as the IO-Link.com site.
Parameters are the key to maximizing performance and stretching sensor functionality on machines through IO-Link. They are typically addressed during set up and then often underutilized because they are misunderstood. Even users familiar with IO-Link parameters often don’t know the best method for adjustment in their systems and how to benefit from using them.
Using parameters reduces setup time
During standard installation, users must acquire all manuals for each IO-Link device and then hope that all manufactures provided detailed information for parameter setting. All IO-Link device manufacturers are required to produce an IODD file, which can be accessed through the IODD Finder. This IODD file provides a list of available parameters for an IO-Link device which will save the user time by eliminating the need for manuals. Some IO-Link masters can permanently store IODD files for rapid IO-Link parameterization. This feature brings the parameters into an online webpage and gives drop down menus with all available options along with buttons for reading and writing the parameters.
Maximize functionality of the device
Setpoints can be changed on the fly during normal operation of the machine which will allow a device to expand to the actual range and resolution of each device. Multiple pieces of information can be extracted through IO-Link parameters that are not typically available in process data. One example being an IO-Link pressure sensor with a thermistor included so that temperature can be recorded in the parameters while sending normal pressure values. This allows the user to understand the health of their devices and gather optimal information for more visibility into their processes.
Allows for backup and recovery
IO-Link parameterization allows the user to read and write ALL parameters of IO-Link Data of the device. For example, a two-set point sensor will typically have a teach button/potentiometer that technically limits adjustment for only two parameters and cannot be backed up. This method leaves devices vulnerable to extended downtime from loss of setpoints as well as adding complex teach functions that are not precise. IO-Link parameterization on the other hand pulls teach buttons/potentiometers into the digital world with precision and repeatability. Some IO-Link master blocks have a parameter server function that backs up device parameters in case a sensor needs to be replaced, ultimately providing predictive maintenance, reduced downtime, and easy recipe changes quickly throughout the process.
Using IO Link parameterization is highly important because it reduces setup time, maximizes the functionality of the IO-Link device, and allows for backup and recovery of the parameters. Implementing parameters results in being more cost effective and decreases frustration during the installation process and required maintenance. These parameter functions are just one of the many benefits of using IO Link.