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Ligth Barrier vs. Radio: Data Transmission with Profinet

Modern production systems work with mobile robots or other moving components. They can be flexibly and agilely adapted to new products and requirements, enabling optimized processes and maximum efficiency. Wireless communication has long since established itself as the better alternative to cables for data communication in such machines and systems. In a technology comparison of ligth barriers and intelligent radio data transmission, we will explain the advantages and disadvantages of these two wireless technologies for Profinet data transmission.

How Do Light Barriers Work?

Light barriers are part of optical data transmission systems. Each unit consists of a transmitter and receiver facing each other to send and receive data, which is usually transmitted via a pulsed laser beam. Different frequencies are used to prevent interference due to reflection or mutual interference. Light barriers can be used to transmit data over a distance of up to 300 meters (approx. 984 feet). To ensure reliable operation, both units must be precisely positioned, and there must be an uninterrupted line of sight.

What Is Intelligent Radio Data Transmission?

Intelligent radio data transmission was specifically designed for interference-free data transfer in Profinet networks and other fieldbus protocols. The data packages are analyzed and preprocessed before transmission. This reduces latency and increases the stability of data communication. Short-term interruptions in the radio connection can be automatically filtered out and bridged so that no interference is reported to the controller.

>> More information on the functional principle in the blog post: Using radio data transmission to create stable and reliable automation solutions.

Pros and Cons of Optical Data Transmission

Optical data transceivers transfer data from point to point at speeds of up to 100 MBit per second. To ensure interference-free operation, the optical sensors of the transmitter and receiver units must be free of dust and dirt. This is why optical data transceivers are particularly suitable for clean ambient conditions. If this is guaranteed, the sensors will operate maintenance-free.

A direct and uninterrupted line of sight between the two units must be ensured, ideally also protected from extraneous light. The technology is not suitable for height offset applications. Machines or system components may only move linearly in relation to each other. Optical data transceivers are not suitable for applications with rotary movements. It must also be ensured that the travel paths or position of the controller and IO devices do not vary; otherwise, the narrow aperture angle of the sensors would require complex adjustment of the photoelectric sensor connection. Due to the way they work, ligth barriers only transfer data between two devices. Multipoint networks are not possible.

Intelligent Radio Data Transmission: The Alternative to Optical Data Transceivers

Unlike optical data transmission using photoelectric sensors, wireless solutions also enable transmission between controllers and multiple IO devices in any direction and architecture. The position of the radio devices in relation to each other is also irrelevant, making radio data transmission suitable for freely movable, mobile devices, rotary movements, and offset applications. The wireless connection requires positioning within the range, with no need for an unobstructed line of sight. This enables significantly greater flexibility in system design.

In addition, radio data transmission solutions work reliably and without interference even in dusty and dirty environments. They require no maintenance throughout their entire life cycle. This makes intelligent radio data transmission solutions ideal as an alternative to optical data transceivers, for new systems as well as for retrofitting and modernizing existing automation systems. Radio data transmission provides maximum flexibility in system design and also enables agile adjustments to the production facility. There is no need to readjust or change integration into the network, so production can be resumed as quickly as possible and with no additional downtime.

How Intelligent Radio Data Transmission Differs from Conventional Wireless Solutions


Intelligent radio data transmission is a patented advanced development of conventional wireless solutions. The bandwidth required for data transmission is reduced by prior analysis and preprocessing. This reduces the load on the radio link, avoids fieldbus errors, and increases reliability.” 


You can find out all the details about intelligent radio data transmission and the advantages over conventional radio data transmission in our video:

At a Glance: A Comparison of Light barriers and Intelligent Radio Data Transmission for Profibus Data Transmission

Light Barriers / Optical Data Transmission


Intelligent Radio Data Transmission


Will intelligent radio data transmission also work for your application? Try it out!

Write to us with your requirements. We will quickly and conveniently send you a trial system that you can use to test wireless data transmission directly in your application.

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Our experts will of course also be happy to assist you in person with selecting and implementing your wireless solution. You can reach us by phone at +49 7144 89718-0 or via the contact form. You are also welcome to use our chat. We look forward to hearing from you!

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