IO-Link
What is IO-Link?
IO-Link is an I/O technology for the communication of sensors and actuators with a superior control unit and the HMI (Human Machine Interface). The standard for IO-Link is IEC 61131-9. The standard contains the electric connection data and the communication protocol. IO-Link can transmit signals as well as energy. The communication in IO-Link is serial and bidirectional.
Functionality IO-Link
Within the structure of IO-Link, the IO-Link Master is responsible for the establishment of the connection to the superior network (Industrial Ethernet, Fieldbus). IO-Link devices are connected to the masters via a point to point connection. Non-coated standard cables with three cores are used, which in most cases are already being used which means that no new lines have to be run. The use of already present lines saves money. If energy is to be transmitted to the devices, a standard cable with 5 chores should be used. The specification limits the cable length to 20 m.
Communication
In the standard 24 V signals are used. Two modes are available: Switch mode and Data Package Mode. IO-Link Masters have ports to connect devices. Each port can be used to connect one device. It is possible to use four operating modes per port. In the operating mode "IO-Link", data is transferred between the device and the master. "DI" takes the switch signal of the sensor. Similarly "DQ" triggers an actuator. In the operating mode "Deactivated" the port has no functionality.
Device Description File IODD
An XML description of parameters is available for each device. The files can be found and downloaded with the IODDfinder. With the use of an internet connection, this process can automatically be included in the software tool for parameterization. Communication with the IO-Link device is possible right after downloading.
Types of Data
Four types of Data can be used for IO-Link data exchange: process data, value status data, device data, event data. Process data and value status data are transferred periodically. Device data and event data are exchanged when necessary.
Product OverviewIO-Link is a trade mark.