Ethernet cables are traditionally designed to be fast, yet the data transfer rate is not always the most important element in the factory network. Sometimes small diameters and easy installation matter most. Single-pair Ethernet cables fill this void.
The invention of the steam engine in the late 18th century, electrification and mass production one hundred years later, computer-aided automation since the 1970s and now Industry 4.0: all of these are industrial revolutions have revolutionised the way we work and manufacture and have increased productivity many times over. In so doing, they have tapped into new ‘raw materials’ be it steam power, electricity or the processing power of computers. Industry 4.0 is the big step being taken today. Data is the raw material of the 21st century. It has caused the physical and digital worlds to merge and, at the same time, brought about a rise in networking - every machine and every ‘thing’ exchanges information with others.
This revolution staged on the shop floor has impacted on connection technologies. When every thing is communicating with every thing around it, the number of connections increases exponentially, as do the quality and availability requirements. Yet the data transfer rate does not necessarily change. When it comes to cables, users tend to think “the bigger the better” and buy oversized products. Whereas high-speed cameras used for quality control could benefit from Ethernet cables capable of transmitting 10 gigabits per second, not every sensor needs this maximum data transfer rate: many of them that will be added to machines will be quite simple, sending only on/off type signals, for example. So downsizing Ethernet data cables has become a trend that very likely will make its way into factories over the next few years. Instead of four pairs of cores, single-pair cables have just one pair. One certainly should not expect record speeds from these cables, but one gigabit per second is fast enough for many applications, and certainly for on/off type signals.
Single-pair data cables are perfect as they are low cost and do not take up huge amounts of space. These cables can provide noticeable relief in machines with many sensors and little space. And of course two core are much faster to install than four, which with the exploding number of sensors that have to be connected, could mean major time savings. Another benefit of these downsized cables is their extended length, as connections with conventional Ethernet cables are restricted to 100 metres in length. The further the distance beyond this, the more frequent the malfunctions. This can lead to data errors. Through the latest advances in semiconductor chips from the automotive industry, many of these faults can be corrected in Single Pair Ethernet cables, which means they can be used in lengths of up to 1km.
Ethernet is the future
In any case, Ethernet is the future. Industrial Ethernet is currently growing at 22% a year compared to only 6% growth in fieldbus systems. In 2018, the number of industrial Ethernet systems installed in factories has outnumbered fieldbus systems for the first time ever. New concepts such as single-pair Ethernet can also benefit from this. Single-pair Ethernet cables are not yet available, at least not for use in industry. The automotive industry is already using similar cables in vehicles, but there are as of yet no standards for industrial applications. Newly established working groups are currently examining this. “The first serial products for single-pair Ethernet will be available in two to three years. It goes without saying that Lapp will be one of the suppliers,” promised Guido Ege, Head of Product Management and Product Development.