Connectors
How SPE Links the Smart Factory from Bottom to Top
Today’s factories are modern marvels, displaying the power and capability of highly networked machines. And while much is made of wireless connectivity, copper cables continue to retain the trust of industrial engineering teams. Over the years, many networking technologies have enabled the interconnection of equipment that has streamlined factory automation, increased efficiency, and lowered the cost of goods. Hence, the use of robust, reliable wired Ethernet connectivity is seeing a resurgence in response to factory automation demands for more sensors and actuators.
Ethernet has been in place in industrial automation for some time. It’s found its role primarily at the enterprise level, supporting the data backbone, and in applications where its data throughput delivers clear advantages, such as in vision systems. Fieldbus networks are then attached through PLCs and protocol converters. However, with its four twisted pairs of cables and RJ45 connectors, standard Ethernet cabling and connectors aren’t suited to the full range of industrial equipment in use. Thanks to Single Pair Ethernet (SPE), that’s all about to change.
One Standard for All
SPE takes much of the existing Ethernet standards together with recent advancements such as Time Sensitive Networking (TSN) and adds new physical layers. IEEE 802.cg 10BASE-T1 offers transmission speeds of 10MBits/s over cable lengths of up to 1,000m, making it ideal for point-to-point (PtoP) connectivity in the long link lengths used in the process industry. A variation on this, 10BASE-T1S, allows point-to-multipoint (P2MP) connections, supporting a minimum of eight nodes sharing the bandwidth. At the other end of the scale, IEEE 802.3bp 1000BASE-T1 offers 1Gbit/s speed over 40m of shielded twisted pair (15m unshielded).
Not only does this simplify wiring, thanks to the use of a single twisted pair, but cable installations also are lighter and offer a higher cable density. They can also provide a tighter bending radius than traditional Ethernet cables and alternative fieldbus technologies that rely on more than two wires. As a result, SPE looks attractive at the device and even sensor level.
There is also a provision for power delivery. For classic Ethernet, this is termed Power over Ethernet or PoE. However, this technology relies on the availability of at least two twisted pairs. For SPE, Power over Data Lines (PoDL, 802.3bu) is available, offering between 0.5W and 50W to end devices.
With data and power defined, the final puzzle piece is the connector. While RJ45 may suffice for the office and home, it lacks the robustness and ingress protection needed in industrial installations, not to mention having six connections too many for SPE. Suppliers such as Amphenol have coalesced around IEC 63171-6, a standard supporting two-way and four-way connectors for power and data with transmission frequencies up to 600MHz.
Ruggedized Connectivity
For teams installing and building equipment destined for dusty and wet environments, connectors providing suitable ingress protection are necessary. However, no one wants to cut corners on ease of installation. Amphenol’s range of IP67 M12 push-pull form factor SPE connectors provides robustness for everything from low data rate sensors to gigabit vision system cameras. PoDL is also supported up to 60V/4A.
Fitted with a secure latch providing a minimum retention force of 100N, the connectors also offer 360° EMI shielding. The panel mounting jacks include gaskets and mounting nuts in their zinc diecast housing and are provided in PCB right-angle and vertical termination variants, as well as with solder cups. The plugs support 28 to 18 AWG in the solder variant or 28/7 to 25/7AWG for the insulation-displacement connector (IDC) versions. Cable assemblies are also available with plug-to-pigtail or plug-to-plug options in lengths of 0.5m.
When ingress is less of a concern, engineers should consider the IP20 range of SPE connectors. The PCB mounting jacks come in vertical and right-angle options, allowing sensor and actuator designers flexibility. The plug provides a positive latching, thumb-actuated metal latch that gives 50N of retention force. When mated, these also provide 360° shielding for the signals while supporting 60V/4A in PoDL installations.
Of course, industrial automation still relies on traditional CAT6A four-pair wiring in some applications and switches, demanding connectors that won’t become accidentally unmated. The ix Industrial range of IP6X rectangular push-pull connectors offers field terminable plugs with dual metal latches that are small and lightweight in an ergonomic form factor. Conforming to IEC 61076-3-124, they interface with standard IP20 ix Industrial receptacles. With ten contacts, eight can be used for Ethernet, leaving two spares for power or other use cases.
Compared to RJ45 connectors, designers can space ix Industrial receptacles at almost half the distance (10mm compared to 19mm), are 40 percent shorter than vertical RJ45, and 75 percent smaller in total. This offers greater port density for space-saving designs. They also exceed PoE++’s 100W power delivery requirement (802.3bt).
Conclusion
Thanks to SPE, Ethernet is, at last, becoming an option from the bottom to the top of the factory automation hierarchy, offering industrial engineering teams a chance to simplify equipment installation in factories and production facilities. With their standards-compliant connector solutions, Amphenol provides designers with robust, shielded connectors that are easy to install in the field and offer space-saving innovation on the PCB.