IO-Link trends

Global, manufacturer-independent, and fieldbus-independent: The requirements and expectations for IO-Link technology are high, and in the future, they are expected to extend to the standardisation of even the smallest and most customised applications. Manufacturers are making correspondingly high efforts to make the IO-Link standard a key technology for flexible, secure, and smart manufacturing concepts.

The goal is to establish different IO-Link profiles that offer benefits for end customers, system integrators, and device manufacturers alike. The result for all stakeholders is a range of harmonisation levels for device description files (IODDs) for the control and diagnostics of sensors and actuators in the field.​

These can be divided into three classes:​

• Manufacturer-specific versions with specific IODDs​
• Smart Device Profiles with harmonized IODDs​
• Application profiles for specific applications with community IODDs​

​Thanks to this harmonisation, various requirements can be met for individual IO-Link devices in a specific application. This increases planning certainty for​ users and significantly reduces integration effort.​ The IO-Link Consortium has described the path to application profiles (AP)​ in a roadmap. It envisions the publication of additional Smart Device Profiles (SDPs) and the first application profiles in the coming years.

Over the years, IO-Link has become established as a sensor/actuator communication system. To benefit from IO-Link in the field of safety technology, IO-Link Safety was developed, offering advantages such as reduced wiring, fewer conventional input and output cards needed, and use of analogue measured values for condition monitoring.

Requirements

• 5-pole M12 connectors and uniform software tools to integrate devices from different manufacturers
• A central FS master for devices with different signal outputs
• Compatibility with existing "standards" (e.g. OSSD)
• Automatic check of the stored parameters, authenticity and I/O data structure during port start-up
• Timing of the FS masters and FS devices according to the duration of the self-tests
• Automatic transfer of parameters when replacing defective FS devices

The devices are connected to the IO-Link safety master (FS master). Devices from different manufacturers can be easily integrated via a uniform sensor/actuator interface (M12/5-pole). In the future, a universal software tool will be used for commissioning in order to reduce the number of special gateways when integrating devices. By using a compact FS master, you no longer need a high number of evaluation cards (input and output cards). This reduces wiring and allows for easy analogue value processing. Communication with the FS PLC takes place via the respective FSCP domain.

In compatibility mode, two separate OSSD channels are available as before. Two modes can be selected. Thus, sensors can be configured via IO-Link for easy setup and then operated in OSSD mode for reliable signalling of safety-relevant events.

To ensure safe operation right after start-up, the FS devices are automatically instructed by the FS master during port start-up to check the stored parameters, FSCPs, port numbers and the I/O data structure. IO-Link delays the readiness for operation of the FS masters based on the duration of these self-tests to compensate for the resulting delayed readiness of the FS devices.

Alternative safety products with IO-Link from ifm

With AL200S, ifm has launched its first safety product in the IO-Link environment. AL200S is a safe IO module for PROFIsafe with safe inputs and outputs. It is suitable for the connection of safe mechanical contacts and OSSD sensors.

One of the key factors in the success of IO-Link is the easy wiring of intelligent sensors and actuators using standardised sensor cables. In future, even this may no longer be necessary to meet the increasing demand for fast and uncomplicated data exchange between an increasing number of participants. In the field of automation, mobile communications standards such as IO-Link, 5G or Wifi 6 form the building blocks for real-time M2M (machine-to-machine) communication. IO-Link technology, which was co-founded by ifm, enables remote access to different process values for diagnostics and condition monitoring without any conversion losses and completely controller and fieldbus-independent.

IO-Link is now wireless! This reduces the installation effort to a minimum. Real-time communication guarantees fast reaction times for immediate detection of process value fluctuations. In addition, defective components can be replaced in the shortest time without extensive wiring, thus avoiding long production downtimes. Moreover, downtimes in areas where cables usually wear quickly, such as on AGVs or robots, are excluded.

Wireless Applications

• Automation of processes, e.g. by robots, drones or AGVs (high availability at maximum transmission speed and reduced range)
• Non-time critical monitoring, e.g. of container levels for intelligent planning of waste collection routes (low data volume and current consumption with many participants as well as good energy efficiency with long range)
• Diagnosis, parameter setting and visualisation of process data, e.g. for parameter adjustment in line with the material to be detected (high data volume with few participants and medium transmission speed with medium to small range)

The aim is to have up to five times as many IO-Link devices communicate with a master compared to standard cable connections - at a cycle time below 5 ms. In practical terms, this means that up to 40 devices will be able to communicate with one master via radio. For example, with three masters within one RF area, communication with up to 120 devices will be possible at the same time. Both cyclic data (process data) and acyclic data (on request data) can be transmitted. A range of up to 20 m is achieved between device and master.

Alternative wireless technologies with IO-Link from ifm

The io-key and the Bluetooth adapter are ifm’s first products in this direction. So it is already possible to access the process values of your applications wirelessly via GSM mobile network or Bluetooth. Wireless concepts are particularly important in process and time-critical applications, e.g. in automation, where many participants communicate with each other virtually in real time. ifm can look back on over 50 years of experience in this field of factory automation.