Over the past three decades, technological progress and, in particular, digitalization in automation technology has taken place in huge spurts of innovation. The ever-increasing functionality of the devices and the simultaneous demand for ever more compact housing dimensions also placed greater demands on the connection technology and therefore on M12 connectors. These developed through numerous pole configurations from the 'simple' sensor connection, which was designed as a 4-pin compact direct connection for sensors as early as the mid-1980s, to the universal world standard for the connection technology of data, signals and power in automation components.

Thanks to improved handling, the M12 push-pull concept enables more compact device designs.

© Phoenix Contact

However, in addition to all its advantages, the M12 screw locking of the connectors has one small drawback: the time required for correct screwing. In order to optimize this point, various approaches have been developed in recent years to replace the locking mechanism with so-called 'quick coupling techniques' or to combine it with the M12 thread. However, these remained proprietary solutions that ultimately failed to establish themselves as the market standard. The reasons for this varied - including additional costs, limited availability due to only one manufacturer and, above all, a lack of standardization.

Worldwide acceptance

The worldwide acceptance of the M12 connector is based to a large extent on the seamless standardization through IEC standards. The new IEC 61076-2-010 now creates a harmonized normative integration for all commercially available M12 push-pull quick-connect variants. It makes it possible to connect automation components in future with a consistent standardized push-pull quick connection technology based on M12.

When comparing the M12 push-pull quick connection with a conventional M12 connector with a standard thread, the push-pull variant offers significant time savings during installation. By simply plugging in the connection, users save up to 80 % installation time and therefore also significant costs. Thanks to the improved handling of the M12 push-pull quick-locking system, the device layout can also be made more compact: Firstly, less space is required between individual device ports, and secondly, the device ports can optionally be fully 'recessed' into the device. Both advantages meet the growing demand for miniaturization.

Thanks to IEC 61076-2-010, the M12 push-pull system offers all the designs required for cabling automation components.

© Phoenix Contact

Another advantage of the M12 push-pull quick-locking system is the connection reliability compared to the conventional M12 connector: while a torque tool is required to ensure IP67 protection with an M12 connector with a standard M12 thread, this is not necessary with the M12 push-pull quick-locking system.

Equally important for the end user is the broad and worldwide availability of the M12 push-pull system. This is why leading M12 connector manufacturers have spoken out in favor of supporting IEC 61076-2-010 - the main reasons for this are the manufacturer-independent functional reliability as well as the economic manufacturability due to the proximity to the basic standard -101 and the simple integration into the device.

Components for a consistent topology

The M12 push-pull standard IEC 61076-2-010 is an evolution of the basic standard -101. It references all known M12 standards, such as IEC 61076-2-111 for power connectors (M12 Power) or IEC 61076-2-109 for X-coded M12 connectors. This means that the M12 push-pull quick-locking system is finding its way into signal, data and power cabling in the industrial sector.

The M12 duo contour allows flexible field wiring with M12 screw connectors (left) or by means of push-pull quick locking.

© Phoenix Contact

Here too, it is not only standardization that is the key to success, but above all a consistent system topology. In addition to the aforementioned device ports with Duo contour, the end user also requires overmoulded M12 push-pull cables, connectors for self-assembly and distribution systems in order to implement consistent wiring according to their requirements.

Phoenix Contact presented the first products for device design-in and field wiring at Hannover Messe 2021.

The highlight of the further development of the M12 is that the proven M12 full thread is retained. The push-pull mechanism simply sits in front of it, which makes the switch to push-pull much easier.

Tobias Dietel is Group Manager Product Marketing Industrial Field Connectivity at Phoenix Contact in Blomberg.

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The advantages of the seamless evolution of push-pull technology are particularly evident in the design-in properties of the device connectors: nothing changes in the device - the minor modification for push-pull technology only takes place in the area of the M12 thread. Device manufacturers can continue to use the established M12 device connectors without changing the device design - for example, the two-part modular M12 reflow device connector range. This extends the functionality of the devices without additional effort and offers the end user the freedom to choose whether to implement the field cabling with conventional M12 or push-pull quick-connect technology.

The future of the M12 system

The M12 system will continue to be successively expanded in order to gradually integrate push-pull technology into all M12 product families for field and device cabling. The first M12 push-pull products were presented at the Hannover Messe 2021. On the field cabling side, various overmoulded A-coded M12 push-pull cables are available - in male and female versions, with 3 to 5 poles and in straight and angled versions. For device integration, the corresponding articles and other pole patterns for two-piece THR PCB connectors are already available.

Jürgen Sahm is Senior Specialist Product Marketing, Field Device Connectors, at Phoenix Contact Connector Technology in Herrenberg.

© Phoenix Contact

Thanks to the 'push-pull-ready option', it is already possible to equip devices with additional M12-typical pole patterns in advance. The duo functionality enables users - depending on the availability of the field cabling - to operate the devices with push-pull or conventional M12 screw locking. At the beginning of 2022, Phoenix Contact will expand the portfolio to include shielded variants and connectors for self-assembly. These can be used to wire applications such as analog sensors or devices with a data connection.