Connector, gland, and grip options for industrial-automation cabling
M8 and M12 connectors may have two, three, four, five , eight, or 12 pins (also called positions). Sensors and power supplies generally require three or four pins. For M-series connectors on the ends of Ethernet and PROFINET cables, four or eight pins are needed. In contrast, those on the ends of cables carrying Fieldbus, CAN bus, and DeviceNet data usually have four or five pins. Of course, cables carrying multiple data and power streams may require termination with an M-series connector having all 12 pins.
introduced by Molex so it is sometimes referred to as Molex interconnections in the vernacular. The proprietary Molex Brad series of connectors are based on M12 connectors but replace the threaded sleeve with a more convenient and reliable push-to- lock system. Because the locking does not depend on the operator tightening a thread, it ensures reliability and minimizes the risk of an intermittent signal. Brad connector variations include: ■ Brad Micro-Push M12 connectors — a push-on and pull-off connector providing IP65 protection ■ Brad MX-PTL M12 push-to- lock connectors offering IP65 protection ■ Brad Micro-Change M12 threaded connectors offering IP67 protection ■ Brad Ultra-Lock and Ultra-Lock EX M12 connectors with push-to- lock fittings and O-rings for full IP69K level of ingress protection. Coaxial connectors for high-frequency signals Coaxial cables (fitted with coaxial connectors) are also used in industrial automation for transmitting high-frequency signals — especially those
supporting vibration monitoring and analog signal transmission. Standards abound. BNC connectors have a bayonet fastening that requires a quarter turn to connect or disconnect. They can be used for frequencies of beyond 12 GHz and in some cases up to 18 GHz. DIN 0.4 to 2.5 connectors are very small push-fit connectors suitable for frequencies to 3 GHz. In contrast, DIN 1.0/2.3 connectors are small push-fit radio- frequency connectors widely used in digital telecommunications. Modular and custom cables proliferating for automated machinery With conventional system integration approaches, cables are “made up” — measured, cut, and terminated — onsite during the installation of the automated equipment. That usually means an onsite electrician cuts the required cables to length, strips all their conductors’ delicate sheathing, and fits the cables with the connectors required to join the components at hand. Such in-field cable preparation is time-consuming and leads to variable connection quality. That’s why the trend now is to source modular cable and connector systems consisting of standard cables and factory-fitted
Figure 5: This Brad Ultra-Lock 120108 right-angle connector is a proprietary adaptation of an M12 connector design to boost reliability. (Source: Molex)
In fact, one related connector- receptacle design that’s quite common in the industry is the pin- array-and-socket pair — originally
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