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3 August, 2021

Wireless technology is ‘first’ to transmit Ethernet latency-free

22 June, 2021

Phoenix Contact has developed technology for contactless transmission of data and power which, it claims, is the first that can transmit protocol-independent and latency-free Ethernet wirelessly at speeds of up to 100 Mbps across an air gap of up to 10mm. The NearFi technology can also transmit 50W constantly across the gap.

The couplers can transmit any Ethernet signals – including Profinet IRT, Sercos and EtherCat – with no appreciable latency. It will also be suitable for developments such as TSN and OPC UA.

The technology provides the full duplex transmission – simultaneous transmission in both directions – needed for real-time Ethernet protocols. It does this using two 60GHz connections (one uplink and one downlink) operating in parallel on separate frequency bands.

Other wireless transmission technologies use packet-oriented transmission, resulting in significant latency because packets are first received, then repackaged before being sent wirelessly. At the receiver, the wireless packet must be unpackaged, and output again. This process involves many asynchronous and latency-causing operations. Phoenix says that its synchronous bit-oriented transmission technology eliminates such delays.

Two devices are needed for transmission: a base coupler and a remote coupler. They do not need to be configured and are said to be as easy to use as a connector. A built-in alignment aid ensures that signals can be transmitted as soon as the devices are coupled.

Many NearFi systems can operate in parallel and can coexist with existing wireless technologies such as WLAN or Bluetooth without interference.

One of the first applications is expected to be replacing wear-prone connectors or sliprings, especially when parts are reaching their limits due to contamination, vibration, or frequent contact.

Another potential application is in robotic tool-changers, where connectors need to be connected and disconnected frequently – possibly several hundred times per day – and connector service lives are limited. In such applications, the contacts can become damaged, dirty and misshapen, leading to production stoppages and requiring regular costly maintenance.

Phoenix Contact’s NearFi technology can transmit latency-free Ethernet and power across a gap of up to 10mm.

The NearFi couplers can be mounted easily and flexibly using universal mounting options. Unlike conventional connectors, they can be positioned to face each other from any direction, even rotating in relation to each other. They do not need to be positioned precisely opposite each other, but can face each other with an offset, or at a tangential angle. With robust IP65 housings and M12 connections for Ethernet and power, the couplers can be used in tough environments.

Transmission is possible through non-metallic materials such as glass, plastic and wood, opening up a variety of applications.

The inductive transmission of up to 2A at 24V can be used to power devices such as I/O stations and switches without needing to make contact. The base coupler generates a magnetic field via a coil, which is induced in the coil of the remote coupler.

Active closed-loop control selects the best possible parameters for the power transmission. This means that the power does not reduce with distance, and remains at a constant 50W over the operating range of up to 10mm.

Bright LEDs provide all-around visual signals, indicating the readiness of the coupling link in all directions.

A digital output allows the couplers to be diagnosed via a higher-level control system. A digital input on the base coupler supports defined switching of the remote coupler.

Phoenix ContactTwitter  LinkedIn

One potential application for NearFi is to replace wear-prone connectors in tool-changers



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