The basis of the EchoRing approach is a software technology developed by R3 Communications that is based on a logical token ring method. The token packet (auxiliary packet for controlling deterministic channel access) is also used as an exchange platform for channel states. "Based on the complete channel knowledge thus available, a perfect node - also known as a 'buddy' - can be determined for each transmission for any necessary repetition. Since every node can potentially support every other node, this technology is referred to as 'massive cooperation'," explains Dr. Mathias Bohge, one of the two managing directors of R3 Communications. In this way, a deterministic response time of the system in the order of one millisecond and communication availability of up to 99.9999999% can be achieved using standard radio modules.

At SPS IPC Drives 2017, the Berlin-based company will be presenting the first series product based on EchoRing after two years of development. The so-called 'EchoRing Radio Board', which was developed together with the company Schleicher Electronic, can be used for any system in a similar way to a WLAN module. In a first illustrative application, it serves as the basis for an HMI from Schleicher, in which consumer tablets can be made fit for wireless safety applications using Profisafe. The wireless hardware is based on technology from Texas Instruments, with whom R3 Communications works closely and has thus made the software implementation of EchoRing possible.

When asked what specifically distinguishes EchoRing from other radio systems that are used for wireless safety applications, Bohge replies: "In order to enable SIL conformity despite the volatile wireless channel, the systems usually run according to the 'black channel' principle. This means that a safety layer ensures that the system switches to a safe state as soon as the connection is lost. Existing wireless systems suffer from the fact that this state occurs very frequently - thanks to the combination of tokens and massive cooperation, EchoRing is much more performant here."

Although the first application implemented with Schleicher is aimed at the HMI sector, Dr. Mathias Bohge clarifies: "The application possibilities of EchoRing go far beyond this. Ultimately, the technology can be used wherever cables are too fragile or inflexible." And his management colleague Florian Bonanati adds: "The highly reliable wireless communication also enables new application scenarios, such as closed-loop robot control from the edge cloud." This technology is currently being researched by R3 Communications as part of the 'fastRobotics' research project in a consortium led by robot manufacturer Kuka. The aim is to develop an innovative system solution that enables robots to communicate wirelessly with each other, with sensors in the environment and with mobile devices."

When asked about the cost of EchoRing, Florian Bonanati replies: "It was clear from the outset that our EchoRing solution had to be absolutely competitive with existing cable-based solutions. As we use standard hardware that has already been developed and tested, this cost basis is already lower compared to new hardware developments. In addition, we 'only' achieve the performance through new software. The respective unit price then of course always depends on which performance cluster we have to address and guarantee, as well as on the quantities requested."