The right connectors for the IIoT

In reality, the IIoT is basically real-time data collection made possible by processing and then transmitting data at ever faster speeds to and from increasingly smarter and smaller devices.

The true value of the IIoT, however, goes beyond data collection and transmission. It embraces the complete visibility and control of virtually all electromechanical factors in the manufacturing process. Plant operators can discover unused capacity, reduce maintenance costs and downtime, improve safety, and maximize overall equipment effectiveness (OEE).

A comprehensive view of a manufacturing process or assembly line is accomplished by placing networked sensors on physical equipment to collect data. These sensors perform condition monitoring analysing constant inputs like temperature, vibration, or sound frequencies. This data is transmitted back to a central location or cloud where decision makers can access it. This process requires reliable high-speed connections, often in environments that include dust, noise, temperature changes, and vibration. In some industries, such as food and beverage, there is the additional challenge of frequent high pressure washdowns.

Connectors are the vital link

Connectors act as the vital link between the cables carrying data and the devices that record and communicate information. The demand for faster data transmissions that can accommodate visuals has driven the development of connectors able to support the gigabit data requirements for the latest sensors. To add to the complexity, machines are getting smaller, putting pressure on component makers to deliver greater speed, power, and capacity in an ever-shrinking footprint.

Introduced back in 1985, the M12 connector has built an enviable reputation as one of the most reliable connectors for industrial applications. Originally used primarily by car manufacturers, the M12 has become the industry standard in factory automation, autonomous robotics, communication, measurement and control, and many other applications.

On the plant floor or in the field, personnel need to be able to disconnect existing connectors for maintenance and install new connectors on newly laid cables quickly, especially where connections must remain dust- or water-tight. M12 connectors are easily installable and clearly coded (see below) to reduce the chance of accidental mis-mating. 

M12 coding for signal and data transmission:

- A-coded for sensors, DC power

- B-coded for PROFIBUS

- D-coded for 100Mbit Ethernet and Profinet

- X-coded for 10Gbit Ethernet

M12 coding for power supplies:

- S-Coded and K-Coded connectors are designed for AC power supplies up to 630V/16A. Ideal power connector for applications including: AC motor and drives, motor control switches, and frequency inverters.

- T-Coded and L-Coded connectors are designed for DC power supplies up to 63V DC/16A. Ideal power connector for low-voltage applications including: DC motor and drives, fieldbus Ethernet components, network devices, and LED lighting fixtures.

M12 connectors are available with 3, 4, 5, 8, or 12 pins. The ideal pin count depends on the application. For example, most sensors and power applications use 3 or 4 pins, where Profinet and Ethernet use 4 and 8 pins.

Locking Systems

M12 connectors can have three types of locking systems. These are:

- Push-pull: Locks easily and securely with an audible click indicating that the proper connection has been established.

- Threaded coupling: A threaded nut on the plug is mated with a corresponding set of threads on the receptacle.

- Bayonet: An interconnect mating design that uses pins on the receptacle and ramps on the plug for quick-connect and disconnect coupling.

Options make for versatility

The connector choice for a specific application can be further customized by selecting options. These include termination style such as crimp and screw clamp, housing material such as plastic or metal and contact plating material such as gold tin or optalloy. Then there is the degree of environmental protection against things like dust and water as well as the obvious electrical specification such as current and voltage.

Why M12 connectors are the smart choice for Industry 4.0

M12 connectors have become the preferred connector for today's industrial Ethernet. For data transmission, they are used on the device side – pulling data from devices and transmitting it to the application where data is aggregated to provide useful information to the user. They are also used to transmit high levels of power for extended time periods in applications including motors and drives, motor control switches and low-voltage applications like Fieldbus, Ethernet components and network devices.

Unrivalled ruggedness  - Compared to the RJ45, the other most commonly used data connector, M12 connectors offer superior performance in harsh conditions due to:

- Circular design that shields contacts from contaminants such as dust, moisture, and foreign objects, while also protecting against impact, vibration, UV exposure, and temperature changes.

- Minimum IP67-rated ingress protection against dust and water and up to IP68 and IP69K ratings for demanding washdown environments.

Mating cycle ratings are another important consideration for machine builders. Ratings are determined by the material used for contacts and plating, as well as the thickness of the plating. Cheaper connectors, made with tin plating and copper alloy contacts, will not perform as well as those made with corrosion-resistant materials such as thick gold plating and beryllium copper contacts, which are typically rated for more than 100 mating cycles.

EMI shielding - Hard-wired connections offer some advantages over wireless connections, including the intrinsic security of physical connections and the avoidance of wireless interference. This is especially important because the new IIoT enabled factory is often filled with electromagnetic interference (EMI), also called radio frequency interference (RFI). Unseen and unheard by people, this electronic noise pollution frequently interferes with high-precision sensors already taxed by the physical noise and vibrations of a busy factory floor.

The increasing pervasiveness of EMI places an additional burden on manufacturers to design equipment that both generates as little EMI as possible and ensures that their equipment has reasonable resistance against EMI so that operation isn’t affected where it is a factor.

In order to satisfy these requirements, manufacturers need connectors and connecting cables with sufficient shielding properties.

Compact size  - The Industry 4.0 trend towards miniaturization requires more compact components and connectivity solutions, even as power and data transmission needs grow. Increasingly smaller devices and sensors are transmitting more data, which requires more connection points, which means that connectors have to deliver the same (or more) power density in a smaller footprint.

Originally designed to reduce the size of the 7/8”  connector, which was standard at the time for sensors, the M12 connector has an outside diameter locking thread of just 12mm. Its small footprint makes it well suited for applications with little free space, such as automation control systems, telemetry modules and value actuators.

M12 technology continues to evolve. Machine designers and OEMs are incorporating M12 connectors into new machines, as well as updating existing infrastructure. With backwards compatibility, replacing older and less robust technology like RJ45 connectors is relatively simple and cost effective. Manufacturers of M12 connectors like binder continue to innovate, adding new features to meet the quickly changing needs of the robotics, automation, food and beverage, alternative energy, and cellular communication industries. Positionable, lockable, field wireable connectors, capable of transmitting impressive amounts of data and power, ensure that the M12 will continue to be an essential component of Industry 4.0 and beyond.

David Phillips is managing director at binder UK

www.binder-connector.com