Internet connected devices with advanced sensor and control features are becoming increasingly common in industrial applications. The rise of the Industrial Internet-of-Things (IIoT) is being driven by the availability of more capable wired and wireless connectivity technologies and the need for manufacturers to enhance efficiency, reliability, and productivity through automation. The results of these trends are increased focus of edge-computing and more advanced sensor/control technologies integrated into industrial processes. Realizing a dramatic increase in density of connectivity devices naturally results in the increase in interconnect. Though industrial wireless networks can offset some of interconnect challenges, industrial wireless networks generally need some type of physical connection and wireless is not serviceable in all industrial environments.
A very recent industry-driven innovation in industrial communication is an advancement of ethernet connectivity for demanding applications. Single pair ethernet (SPE) technology is a way of two-way conducted communication at data speeds reaching 1 Gb/s over short distances while offering Power over Dataline (PoDL) in the same compact interface. This new interconnect technology is a leap forward for control, data acquisition, and cloud connectivity for factory, industrial Internet-of-Things (IIoT), robotics, building, agriculture, and other industrial automation use cases.
The main drivers for SPE technology is the demand these applications have generated for robust and efficient bidirectional communication that can enable real-time and secure device-to-infrastructure and device-to-cloud connectivity. Hence, SPE delivers on all of these requirements to enable enhanced analytics and faster error response in a low-profile, cost effective, and easy to install system. Where traditional ethernet requires four twisted pairs of wires to reach 1 Gb/s speeds, SPE technology can deliver 1 Gb/s to a range of 40 meters while offering PoDL with a single twisted pair of wires. These speeds are possible with a single twisted pair as SPE uses 600 MHz of bandwidth for data communication where each Industrial ethernet twisted pair only uses 100 MHz.
Furthermore, PoDL eliminates the needs for a separate power supply at the connected device or additional wiring and the inefficiency of long range power transmission. The current standard of PoDL delivers a maximum of 50 watts to 40 meters with a standard SPE cable and connector. However, there are SPE hybrid cables with M8 connectors that include additional 18 AWG power conductors that can provide p to 400 watts at 60 V to 40 meters. The data pair in these cables can be further shielded from the power conductors, and additional external shielding is possible to limit any powerline noise from engineering the data signal path.
Though changing over entire connectivity solutions in an industrial facility to SPE may not be viable in some situations, there are many industrial applications that will benefit from the compact, low-weight, and high transfers speeds of SPE. New automotive, transportation, railway, and even aerospace systems are a potential market for SPE where the size, weight, and reliability of traditional interconnect solutions are coming at odds with new applications requiring smaller, lower weight, and faster communication links. For instance, an SPE connector is about 20% of the volume of an RJ45 connector. Other applications, such as building automation, where many small, distributed sensors are placed throughout a large and complex facility may be well served by SPE, even over wireless solutions. The reason for this is that wireless solutions still require some type of power source, which may increase the cost and complexity of deploying wireless sensor nodes and result in reduced reliability and much lower data rates.
