With the introduction of Ethernet in automation applications, vertical communication is now possible, from the control level to the field level. Despite the freedom that Ethernet cabling provides, connectors and cables must meet a wide range of requirements. While environmental conditions at the control level are often similar to those in an office, the production area is typically subject to demanding operating conditions. Humidity, high temperature variations, vibrations, and shocks are all part of industrial environments.
Therefore, it is not enough to simply distinguish between cabling components with IP67 and IP20 protection ratings when assessing their suitability for industrial applications. Aspects such as connector housing robustness, strain relief, clamping protection against lateral forces, oil resistance, and EMC protection must be considered. Furthermore, data connectors used in the field must allow for simple and secure connection even under the most severe conditions.
The 8-pin RJ45 connector specified in IEC 60603-7 [1] is standard for Ethernet cabling and is available in Cat. 5 and Cat. 6 versions compliant with ISO/IEC 11801:2002 [2]. Phoenix Contact offers a complete product range in this field with IP20 protection ratings for wiring inside control cabinets and IP67 for ruggedized field cabling. The product range includes connectors with quick-connect technology, pre-assembled cables, patch panels, and junction boxes.
Cable Types for Ethernet and Profinet:
Symmetrical copper cables are used in industrial Ethernet cabling. Twisted-pair cables with 2 or 4 twisted pairs are the most common, meeting at least the requirements of Cat. 5 according to ISO/IEC 11801:2002. These cables are equipped with a braided shield and protective aluminum foil (SF/UTP cable). In Cat. 6 cables, the wire pairs also have an aluminum foil shield (s/FTP cable). In the 4-pair twisted-pair version, both cable types can also be used for Gigabit Ethernet. For Profinet cabling, 4-wire star cables with a conductor cross-section of 22 AWG have been specified, which also meet the requirements of Cat. 5.
Cable structures for Ethernet and Profinet.
For
Phoenix Contact, within the Profinet User Organization (PNO), has led the specification of a new RJ45 connector with an IP67 protection rating and a push-pull locking system, suitable for Profinet-based Ethernet networks [3]. The connector, available in metal or plastic versions, is recommended by organizations such as AIDA (Automation Initiative for German Automotive Manufacturers) for Profinet cabling in their production systems.
IP67 Ethernet cabling, the M12 connector can be used as an alternative to the RJ45. The M12 connector with D coding has already been defined for Industrial Ethernet in its 4-pin version according to IEC 61076-2-101-am1 (correction 1) [4]. In addition to the push-pull RJ45 connector, the PNO has also specified the M12 version for Profinet cabling. Besides being IP67 rated, the M12 connector, already established in the sensor/actuator and fieldbus cabling field, is characterized by its compact dimensions and excellent vibration resistance. However, not all versions are suitable for use in Ethernet networks, where transmission properties must meet at least Cat. 5 according to ISO/IEC 11801:2002.
Phoenix Contact's M12 components for Industrial Ethernet have been specially developed to meet these requirements and thus offer a high level of reliability for the application.
8-Pin Connector for Gigabit Ethernet.
For the Fast Ethernet 100BaseT standard, which supports a transmission speed of 100 Mbps, one pair of conductors is used for transmitting and one pair for receiving. 4-pin connectors are sufficient for this. If higher transmission speeds are required, 8-pin connectors must be used, for example, those that support Gigabit Ethernet (1000Base-T) with a transmission speed of 1000 Mbps. Cat. 5 transmission speeds according to ISO/IEC 11801:2002 also meet the Gigabit Ethernet requirements. The 8-pin M12 cabling for this Ethernet cabling is A-coded, which is common in sensor and actuator wiring.
For M12-based Ethernet cabling, Phoenix Contact offers shielded 4- and 8-pin components according to Cat. 5: connectors, pre-assembled cables, control cabinet bulkheads, and PCB connectors for printed circuit board mounting. Thanks to Quickon quick-connect technology, the connector can be mounted without special tools, even under the harshest industrial conditions. Pre-assembled cables and cable glands with M12, RJ45, and combination connectors allow the use of both interfaces in a network.
Figure 3. A quick on-site connection via the Quickon quick connection.
Quickon Quick Connection:
Phoenix Contact's Quickon M12 and RJ45 connectors are equipped with the same quick-connect technology, meaning both connectors can be easily used in parallel within the same installation. Both the M12 and RJ45 connectors in the Quickon range meet Cat. 5 requirements according to ISO/IEC 11801:2002, are shielded, and are available in 8- and 4-pole versions. They allow wiring of AWG 26 and 22 for both solid and stranded conductors, meaning they can be used for all industrial Ethernet transmissions, in Ethernet-based fieldbus systems such as Profinet and Ethernet/IP, as well as in Gigabit Ethernet networks.
The conductors are fed through the input channels of the housing, and the conductor ends are cut flush with each other. These are then pressed onto the blades when the housing is closed, thus establishing the connection.
References
[1] IEC 60603-7:1996-11 Connectors for frequencies below 3 MHz for use with printed circuit boards – Part 7: Detailed specification for connectors, 8-way, including free and fixed connectors with common joining properties, with quality assessed. Geneva/Switzerland: Headquarters of the International Electrotechnical Commission.
[2] ISO/IEC 11801:2002-09 Information technology – Generic cabling for customer installations. Geneva/Switzerland: Headquarters of the International Electrotechnical Commission.
[3] www.phoenixcontact.de/industriestecker/216_6500
[4] IEC 61076-2-101-am1:2006-02 Correction 1 – Connectors for electronic equipment – Part 2-101: Circular connectors – Detailed specification for M8 circular connectors with screw or snap-in connection, M12 circular connectors with screw connection for low-voltage applications. Geneva/Switzerland: Headquarters of the International Electrotechnical Commission.
Author:
Eva Andueza, Product Manager at Phoenix Contact, SA.
