Battling big data bottlenecks

Ethernet is becoming increasingly common as a communications standard within industrial automation. Where once, until relatively recently, it was reserved for the top levels of monitoring and control units, manufacturers of sensors, cameras and other industrial devices are looking to connect their products via Ethernet at the top field level. And field clients are becoming smaller, whilst being required to achieve even higher data transfer rates.

In response, Harting has launched a new M8 D-coded connector. Miss M8ty is a small Ethernet connector for applications from the cloud right down to all sensors.
Miniaturised devices (such as camera systems, sensors, switches, I/O boxes and decentralised industrial PCs) are not only becoming continually smaller, but must satisfy the increased specifications of digitalisation and generate significantly more data than even just a couple of years ago.

Standard practice

Until now, it has been standard practice to enable device communication at the top field level via Bus systems. This required translating field level signals into control level Ethernet protocols and vice-versa. It is now possible to cut out this step and connect the new, miniaturised field clients directly via Ethernet. This results in higher data transfer rates, which require modified connector systems.

There are really only two IP67-protected approaches to consider: an additional RJ45 protected in an enclosure, or a M12 pin connector. These connectors are now too large for many applications: some modern industrial cameras used for identification and positioning have grown so small that the power and data connectors are restricting miniaturisation of their enclosures and actually take up most of the space.

M8 connectors are used in many applications at the field level, at least for signal forwarding. The new D-coded M8 connector features a strong metal enclosure with continuous shielding and 0.8 mm diameter contacts, which enable end devices to be supplied with 100 Mbit fast Ethernet. To avoid having to find extra space for the additional power ports, the D-coded M8 connector supports Power over Ethernet (PoE) and can feed field clients simultaneously with power and data.

This offers device manufacturers the right connector system to make the next steps in miniaturisations a reality. On the circuit board, the M8 is about 30% smaller than the M12 it is designed to replace. Whilst that doesn’t sound like much, if you combine different M8 ports on an I/O box, the sum of the reduced modular spacing leads to dramatic space savings. On the device-side, users can choose between two flange sockets in heights of 9mm and 13mm. This allows other connectors of different heights to be used, eliminating the problems of differing distances.

Initially, the M8 D-coded connector will receive the familiar threading used by pin connectors. However, as Harting has had good experiences with a push-pull locking mechanism used on its larger M12 counterpart, the M8 will shortly feature this fast and easy mechanism too; it offers easy access when connectors are arranged next to each other within a very confined space.

The cable components of connector systems must also be modified. Accordingly Harting is to release its own ad-hoc field assembly connector in the form of a displacement termination under the name HARAX.

Backward compatibility

To ensure backward compatibility of the new version of the M8, the D-coded version is also designed with a protocol in accordance with IEEE 802.3, and a connector designed according to the specifications of PAS IEC 61076-2-114.