IO-Link

What is IO-Link?

IO-Link is an open industrial digital communication protocol defined in the international standard IEC 61131-9 that offers bi-directional and point-to-point connectivity between binary sensors (on/off), analogue sensors (0 to 100 %) and actuators to an IO-Link Master. The IO-Link Master is connected to a control-level fieldbus like PROFINET, Modbus, Ethernet IP and others, creating a interface between the field devices and the control system, simplifying the connectivity and reducing cabling costs.

What are the main advantages of an IO-Link device and why you should use it?

Industrial sensors and actuators can provide valuable data besides its main measured value, however, the conventional digital sensors and analogue transmitters are only capable of transmitting one type of information at time. IO-Link sensors and actuators can transmit secondary information to a control system, like the operating hours, alarms, status and events, making it easier to program a calibration, maintenance or a replacement of a critical component. Besides that, IO-link devices can be easily accessed, programmed and operated remotely, almost in a plug-and-play way.

Analogue signals are susceptible to electrical noises and electromagnetic interferences, requiring a special shielded cable. In IO-Link data is transmitted digitally through a 24V pulse modulated signal (UART), making the communication very robust and reliable, because of that, no special cables are needed, usually a standard 3 or 4-wire M12 cable is used, however, other types of connectors such as M5 and M8 can also be found in IO-Link devices.

Because IO-Link transmits the measured value digitally, no accuracy is lost when transmitting analogue values. The information received by the control system is exactly what is being measured, without any deviations caused by analogue-to-digital converters.

Below it is listed the main specifications of IO-Link systems:

• Bi-directional point-to-point communication
• 24V pulse modulated signal (UART)
• Up to 20m distance between IO-Link master and field devices
• 3 or 4-wire interface using standard M5, M8 or M12 unshielded cables
• Remote access to the device parameters, status, warnings, and events

IO-Link devices at Automation24: What do you need to start using it?

Automation24 has a wide selection of IO-Link sensors under the category sensor systems including pressure sensors, volumetric flow meters, compressed air flow meters, laser sensor and many more.

For integrating IO-Link field devices to a control system bus, a compatible IO-Link Master should be selected based in your existing fieldbus communication protocol and the required number of inputs/outputs. For connecting the sensors and actuators to the IO-Link master, you will find in the category connection technology a diverse selection of competitively priced sensor / actuator wiring solutions.

For configuring single-devices, a USB IO-Link interface ZZ1060 can be used in conjunction with the parameter setting system software QA0011 from the manufacturer ifm.