IO-Link with Bihl+Wiedemann: easy, flexible, fieldbus-independent

IO-Link devices are nowadays common in machines and systems. This is because IO-Link allows sensors and actuators to be connected to the control level via a powerful point-to-point connection. Find out more about the general advantages of IO-Link and the associated advantages here.   


This page mainly deals with the following question: What is the best way to integrate IO-Link? Bihl+Wiedemann offers you a sophisticated concept for this: IO-Link can be embedded perfectly in ASi-5 and our user-friendly PC software – from the device to the PLC or cloud. Our solution is suitable for all fieldbus systems, e.g., PROFINET, EtherNet/IP or EtherCAT. In addition to fieldbus independence, you benefit from freedom in the choice of topology, reduced wiring complexity without switches, and a smart power supply concept. Other advantages of our solution include reduced IP management complexity and low-cost IO-Link masters, which we provide with 1, 2, 4 and 8 ports. Numerous technical features also enable you to commission IO-Link devices with maximum convenience. For us, one thing is certain: There is no smarter and more economical way to integrate IO-Link.

Integration independent of system and manufacturer

IO-Link modules from Bihl+Wiedemann feature interfaces for almost all standardized fieldbus systems found in industrial automation technology, no matter which control system is used. System- and manufacturer-independent use is made possible by the ASi-5 technology, which also enables significantly faster transmission of larger data volumes. This means that many applications can be implemented easily and cost-effectively.

Advantages at a glance

Extremely simple commissioning

IO-Link masters can be easily integrated using our convenient configuration tool. For example, you can easily open the IODD and get graphical support for the parameterization of IO-Link devices. Live device parameterization gives you direct control over the settings while being online.


Automatic parameterization when replacing devices

Our PC software makes it easy to copy and reuse parameters from IO-Link devices. This applies both within projects and across various projects. The copy function saves a lot of time and reduces parameterization errors, especially when using many IO-Link devices.

IT interfaces

All our ASi-5/ASi-3 Gateways have an OPC UA server and a REST API as IT interfaces. This enables seamless integration into IT systems, such as cloud-based databases. Process, parameter, and diagnostic data from the IO-Link devices can therefore be transferred easily and cost-effectively to the cloud or HMI – a prerequisite for modern systems in the age of Industry 4.0.

Reduced IP management complexity

Well over 100 ASi nodes with up to 8 IO-Link devices each can be connected to our gateway via 2 ASi circuits. All signals are transferred compactly in bundles to the PLC. This way you have to assign and manage only one IP address.

wiring concept

The amount of effort required for wiring is reduced because all nodes – IO-Link devices, standard sensors and safety modules – are connected to an unshielded 2-core cable using piercing technology. Because no connectors are required, you also save costs and valuable resources. Besides, the maximum IO-Link cable length of 20 meters plays a secondary role in our case because you can distribute the IO-Link masters anywhere on the AS-Interface cable with up to 200 meters in length.

energy distribution

In round cable solutions, the respective connector indirectly determines the "limit" for individual IO-Link masters and for the total current of all IO-Link masters connected in series. With ASi, no loop-through from module to module is needed . The AUX supply is done over reverse polarity protected profile cables, so each IO-Link master draws its energy individually – at 20 A per AUX cable.


While common IO-Link masters are only available from 4 ports or more, ASi also offers the possibility to efficiently integrate 1- or 2-port IO-Link masters. This means that even distributed individual IO-Link devices can be perfectly integrated and no resources are wasted in terms of sustainability. You also enjoy great freedom in the choice of topology and can implement a star, ring, line and network structure, for example. You also gain maximum flexibility through the fieldbus independence of our IO-Link masters.

overall costs

Our IO-Link masters with 4 ports are, for instance, about 50 % cheaper than comparable modules from other manufacturers. This means that the costs for our gateway are recovered, for example, from just 3 IO-Link masters with 4 ports each. You also reduce your installation workload and benefit from the elimination of switches and pre-assembled cables. Click here to view our main cost comparison.


Avoid unused ports and increase flexibility

The simple integration into AS-Interface means no more unnecessary IO-Link masters. Moreover, our IO-Link masters (e.g., BWU4386), can be used for a number of other applications, because ports that are not required for IO-Link can be used as standard I/Os:

  • Every M12 socket has two signals, each of which can be configured as I/O and IO-Link as needed.
  • The module can also be used as a 16-I/O hub for standard digital signals.

  • Thanks to the many configuration possibilities, you do not need any additional standard digital modules, which are expensive.

Instead of connecting IO Hubs to IO-Link Masters, use our I/O modules directly

In order to collect many digital I/Os, IO hubs and IO-Link master ports are often used - there is great potential for optimization here. Simply use an ASi-5 Self-configuring I/O Module from Bihl+Wiedemann: The 16 digital signals of the BWU4230 can be used as inputs or outputs in any desired way - and can be integrated without the detour via IO-Link. By simply integrating digital I/Os via ASi, you do not need any additional IO-Link masters and also transmit the standard signals significantly faster. At the same time, there is no need for M12 connection cables between IO-Link I/O hubs and IO-Link master ports.


The maximum IO-Link cable length of 20 meters is also irrelevant. Find out here why this is the case.


More information

Save valuable resources

The flexible configurability of the IO-Link module offers many advantages. Using AS-Interface also means you need less costly connectors and cables, thereby significantly reducing installation times and material costs. This way, you can save valuable resources such as copper and plastic, which are needed for manufacturing. Even the energy consumed during cable production is significantly reduced. And last but not least, there is a positive environmental effect when it comes to disposal – less waste is generated.

IO-Link with Bihl+Wiedemann

  • The IO-Link master is integrated as an ASi node into the ASi network

  • IO-Link devices can be integrated into the ASi network along with standard sensors, standard actuators and safety components

  • All process data (up to 32 bytes per port) of the IO-Link devices is available via the cyclic ASi communication.

  • All IO-Link parameters can be conveniently adjusted through the B+W Software Suite or acyclically via the control system

  • Diagnostic information from IO-Link available via ASi

  • Our IO-Link masters can be optimally combined with IO-Link devices from any manufacturer

  • If an IO-Link device needs to be replaced, its parameters are stored in the IO-Link master and are transferred automatically to the new one.


IO-Link products

All IO-Link masters offer up to 32 bytes of cyclic process data per port and up to 4 x 16 bits of usable data are available in 1.27 ms each. The Bihl+Wiedemann software suites always enable convenient parameterization.

IO-Link Master mit 4 ports / 8 ports

for use in the field


ASi-5 Module with integrated IO-Link Master, IP67

  • 4 × IO-Link ports, IP67, e.g.:
    • 2 × IO-Link ports Class A, 2 × IO-Link ports Class B
    • 4 × IO-Link ports Class A
  • 8 × IO-Link ports Class A in one housing (BWU4386)
  • Additional I/O signal on pin 2


Product selector

IO-Link Master with 1 ports / 2 ports

optimized for the cable duct


Active distributor ASi-5 / IO-Link Master in IP67

  • 1 IO-Link port Class A, supply of the IO-Link ports out of ASi
  • 1 IO-Link port Class B
  • 2 IO-Link ports, z. B.: 1 IO-Link port Class A, 1 IO-Link port Class B


Product selector

IO-Link Master with 4 ports

for the control cabinet


ASi-5 Module with integrated IO-Link Master

  • 4 × IO-Link ports, IP20 (BWU3843)


Product selector

ASi-5/ASi-3 Gateways

  • Compatible with existing networks

  • 1.27 ms cycle time for up to 384 input and 384 output bits

  • Most powerful platform from Bihl+Wiedemann


Pre-wired StarterKit ASi-5 / IO-Link


  • Set consisting of:
    • ASi-5/ASi-3 PROFINET Gateway (BWU3847)
    • ASi-5 Module with integrated IO-Link Master with 4 Ports, IP67, M12 (BWU4067)
    • Bihl+Wiedemann Software Suite for Configuration, Diagnostics and Commissioning (BW2902)
  • Starter kit is shipped fully assembled and wired in a convenient case
  • Cost-effective version for starting with ASi-5
  • Sufficient space for installing your own IO-Link sensor

André Bideaux, member of the Bihl+Wiedemann sales team, presents the advantages of our IO-Link solution and two new products: The 1-port IO-Link master (BWU4748), which is powered entirely from ASi, and the 8-port master (BWU4386).


Video length: 1:08

Bihl+Wiedemann IO-Link masters can be optimally combined with IO-Link devices from various manufacturers. Paul Werge will give you several examples as to how easy it is to parameterize the IO-Link devices. For a Festo valve terminal, a Zimmer gripper and a Banner tower lamp


Video length: 1:37

IO-Link Safety solutions from Bihl+Wiedemann

IO-Link Safety is an extension of IO-Link. There is an additional safety communication layer on the master and device side. These become the "Fail-Safe (FS) master" and "Fail-Safe (FS) device". Bihl+Wiedemann is in the process of developing its own "FS master". IO-Link is already a perfect match for the safety components of Bihl+Wiedemann.

FAQ about IO-Link

The open IO-Link interface requires only a simple standard industrial cable. Intelligent sensors and actuators can be connected in a cost-efficient manner on an unshielded three- or five-wire cable. For point-to-point communication, each IO-Link device needs an IO-Link master.

The IO-Link master handles the communication to the intelligent sensors and actuators. It enables parameterization, diagnostics and access to the cyclic data by means of a connection to the control system.

Reduced machine-related costs

A cost-efficient standard cable establishes a connection up to 20 meters long between the IO-Link master and IO-Link device.


High machine availability

Downtimes are reduced because when a defective IO-Link device is replaced, its parameters are automatically transferred to the new sensor by the IO-Link master or control system.


Efficient operation

IO-Link devices can be positioned in the machine directly at the work site. These do not have to be accessible for parameterization.


Demand-oriented maintenance

Continuous diagnostic data of the entire process lengthen maintenance intervals, since systems and machines need to be maintained much less frequently due to the automatic readjustment via IO-Link


More information about the advantages of IO-Link

It is possible to extend existing bus systems. As a prerequisite, the system mapping of IO-Link for the respective bus system must be already implemented. It is particularly easy to use IO-Link in conjunction with the ASi intelligent wiring system. Thanks to piercing technology, corresponding IO-Link masters can be easily retrofitted where they are needed.

IO-Link is mainly used in industrial production automation for communication with sensors and actuators.

It is possible to extend existing bus systems. As a prerequisite, the system mapping of IO-Link for the respective bus system must be already implemented. It is particularly easy to use IO-Link in conjunction with the ASi intelligent wiring system. Thanks to piercing technology, corresponding IO-Link masters can be easily retrofitted where they are needed.

Do you have questions about our products and solutions?

ASi – A resource-saving technology

Thanks to the greatly reduced wiring effort with AS-Interface, you save assembly and material costs. This saves valuable resources.


More information!