Ethernet is the most popular wired network standard for Industrial Internet of Things (IIoT) networks, offering strong performance and proven reliability. In addition to this, Power over Ethernet (PoE) reduces cabling by supplying power to sensors and IIoT endpoints over the same Ethernet cable. Ethernet has also become a standard in passenger cars, often replacing the serial Controller Area Network (CAN) protocol. This offers significant advantages for autonomous driving and advanced driver assistance systems (ADAS), thanks to the reliability and high data rate of Ethernet.
However, in large IIoT networks, Ethernet bundles can be so large, heavy, and complicated that the bundles can become obstructions weighing down equipment, requiring auxiliary bracing. This is especially troublesome for automotive applications, where extra weight and space decrease capacity and mileage. In industrial transportation applications such as trucks, passenger and freight trains, and airplanes, the auxiliary size and weight of the cables can be large enough to have to be compensated for in the system design, increasing costs and slowing down preparation times.
To get around these issues, manufacturers have introduced Single Pair Ethernet (SPE) cables and connectors that also support Power Over Data Lines (PoDL). The SPE provides high-speed data transmission, such as power, over a single twisted pair of conductors. The article explains the benefits of EPS for industrial and transportation applications. Now, 2 SPE connectors from Phoenix Contact will be examined as suitable 2 SPE wires for SPE applications.
Comparison of SPE and usual Ethernet
Ethernet is the most popular wired network standard for commercial and industrial local area networks (LANs). The most widely used versions are 10/100Base-T Ethernet, which uses 2 twisted pairs to transmit data, and Gigabit Ethernet, which uses 4 twisted pairs. As industrial automation systems demand faster speeds, Gigabit Ethernet with PoE has become more popular for connecting computers to sensors. In general, twenty-four AWG copper wire is used for twisted pairs. These 8 wires are typically encased in industrial grade CAT5e cable covered with foam tape and foil shielding. In a huge industrial facility, you can see hundreds and hundreds of these cables strung all over the building. These bundles of cables can be heavy, and instead of being routed across the floor where someone might trip over them, they are bundled into harnesses that are attached to walls and equipment. These bundles can weigh fifty pounds (lbs.) or more, and if the added weight of jumper cables is not taken into account, they can strain or break the cable support system or even bring down equipment.
In addition to this, the usual Ethernet cables have a length limit of one hundred meters (m). In larger industrial facilities and building automation systems, repeaters are sometimes required to extend the reach of Ethernet cables to reach remote sensors. This increases the difficulty of the system and also introduces another maintenance point. With the added time and expense involved in running these thick and heavy cables, it is obvious that an alternative wiring procedure is required.
The SPE provides bi-directional data and transmits power using a twisted pair cable. It accepts cable lengths of up to XNUMXm, extending the range of networked sensors without the need for repeaters. This significantly reduces weight and eases installation, making it easier to design, giving maximum power efficiency, a smaller footprint, and lower setup and maintenance costs compared to conventional Ethernet. Although industrial systems may use shielded jackets to keep cable bundles from interfering with each other, lightweight unshielded cables are acceptable as well. This is an advantage in automotive applications as it allows for the use of lightweight cables that can be more easily routed in tight areas such as under seats and running boards. With the combined benefits of a smaller and lighter cable, as well as delivering high-speed data as well as power in one cost-effective pair of cables, SPE is expected to become a popular industrial communications standard, if not dominant.
SPE Basics
The formal IEEE specification for the ten megabits per second (Mbit/s) SPE is 802.3cg. Supports full duplex data communication up to XNUMX m.
The IEEE 802.3bw rule accepts full duplex data communication of up to one hundred Mbits/s for cables up to fifty m. It is targeted at high speed sensors in industrial applications and certain automotive applications.
The IEEE 802.3bp rule supports full duplex data communication at speeds up to XNUMX Mbits/s for cable lengths up to XNUMX m. With this length of cable, it can be applied to certain industrial sensor applications, but is uniquely suitable for high-definition video, as well as small aircraft and commercial automotive applications where high-speed sensor data must be transmitted over a fairly short distance.
IEEE 802.3ch currently supports up to ten gigabits per second (Gbps) with cable lengths up to fifteen meters. It is similar to 802.3bp, but includes the physical (PHY) layer. This is eminently focused on commercial automotive and industrial transportation applications, where high data rates, smaller cable diameters, and most importantly, lower weight are key system design considerations.
SPE with PoDL powers the sensor or Ethernet endpoint over the same twisted pair, with the amount of power delivered determined by the length of the cable and the gauge of the wire. With a maximum length of XNUMX m and a XNUMX AWG cable, the IEEE specification leaves a power of XNUMX volts and XNUMX watts at the end point.
SPE industrial hardware
SPE industrial connections do not use RJ45 connectors, but rather the new IEC 1 TXNUMX connector standard. Phoenix Contact supplies a family of SPE connectors and cables intended for industrial applications.
For industrial SPE applications requiring IP67 resistance, Phoenix Contact offers a true M8 connection using the one million one hundred sixty three thousand seven hundred ninety three SPE M8-two insert with the one million four twelve thousand five hundred two M8 housing (Figure 1 ). The combination of the casing assembly and the insert gives an IP67 protection, suitable for quite difficult industrial environments. The lightweight set is also suitable for aviation and transportation systems.
The connector set can provide PoDL up to seventy-two volts at four amps (A) and is rated for temperatures ranging from -85°C to +8°C, making it suitable for powering IIoT endpoints and data nodes. sensors in outdoor environments. The popular M8 connector format makes it easy for system manufacturers to retrofit existing sensors and equipment with M8 connectors to SPE. The SPE connector assembly uses a standard D-coded MXNUMX-two SPE connector pattern to ensure that only SPE cables are inserted into the connector assembly.
Enterprise SPE Hardware
SPE is also appropriate in enterprise systems, including office environments, where smaller diameter, lighter cables are easier to build and run. IP67 industrial applications can easily interface with these business systems using the exact same SPE network. For business applications that typically require IP20 protection, a convenient solution is Phoenix Contact's XNUMX SPE Modular Connector, a XNUMX soldered IEC connector. through-hole with a locking clip to ensure a solid cable connection (Figure two).
The M8-dos insert is keyed to prevent misconnection. The connector has 2 gold-plated copper alloy pins that keep contact resistance to a minimum, allowing it to provide PdL of up to seventy volts at four A. The M8 housing is brass with a nickel plating for resistance to corrosion.
The one million one hundred sixty-three thousand seven hundred and ninety-seven is compatible with any and all current SPE connector specifications of 802.3cg/bu/bw/bp. It is built to withstand fairly harsh environments, with insertion and removal cycles detailed in over 20, is IP85 rated, has an operating temperature range of -2°C to +XNUMX°C, and measures five x eight hundred and thirty five x fourteen.XNUMX mm. This makes it suitable for solder mounting on single board computers (SBCs), such as programmable logic controllers (PLCs), where leads are interchanged sporadically. Examples of scenarios where this is useful include manufacturing facilities that may need to be reconfigured for different product sets.
SPE cables for IIoT
For short SPE connections, Phoenix Contact supplies the SPE cable one million one hundred eighty three thousand eight hundred eight of two m. This cable supports PoDL up to 2 volts at XNUMXA and has XNUMX SPE receptacles on each end of the cable (Figure XNUMX). Whereas conventional Ethernet has plugs at the ends of the cable and receptacles at the ends of the cable, the SPE hardware is reversed.
The cable sheath is made of polyurethane, resistant to ultraviolet (UV) light, abrasion and most solvents. Polyurethane cables are also resistant to shrinking and cracking from exposure to sunlight and water, as well as the abuse common in industrial environments. The cable is protected from electromagnetic (EM) interference by a tinned and copper braided shield that is wrapped in plasticized aluminum foil. This makes it suitable for electrically noisy environments, especially when combined with other high-speed cables.
The cable receptacle contacts are copper alloy and accept 802.3cg compliant ten Mbit/s data transmission as well as 802.3bw 802.3 Mbit/s speeds. The highest transmission speed is XNUMXbp thousand Mbits/s, which makes it suitable not only for sensors, but also for high-definition (HD) video surveillance equipment.
While the cable jacket is impervious to water and dust, as well as being flame resistant to UL94V0, the cable assembly is IP20 rated due to the cable termination connectors. Each connector has a locking clip to securely connect the cable to the point and end of the jack. This locking mechanism is part of the SPE connector rule to prevent accidental removal in high traffic environments. The cable is designed to operate at temperatures between -85°C and +XNUMX°C and to carry out up to XNUMX insertion and extraction cycles. It is suitable for use indoors with patch panels, thus for connections between IIoT sensors and SPE junction boxes.
For applications that require a longer cable, Phoenix Contact offers the XNUMX m XNUMX SPE cable, which has exactly the same specifications as the XNUMX.
Conclusion
The move to SPE in applications such as IIoT, automotive, and enterprise helps designers meet the need for high-speed connectivity solutions that are lighter, smaller, and simpler to use, while reducing the cost. However, designers must exercise caution when choosing the connectors and cables they use when deploying SPE-based networks to ensure reliable connectivity in physically harsh and electrically noisy environments.
As shown, connector alterations exist that allow IP20 rated enterprise systems to easily interface with IP67 industrial control systems with true M8 SPE connectors, giving seamless connectivity and power supply in both environments. . With the added capability of PoDL, SPE connectivity makes it easy to deliver power and data to IIoT endpoints in enterprise as well as industrial environments without the need for auxiliary cabling, making deployments much easier and faster.
