Meeting the connectivity expectations set by today's industrial applications

4 mins read

The prevalence of industrial control/automation is growing in all geographic regions across the globe as, in order to simultaneously reduce operational expenses and boost productivity, companies look to offload some of the tasks that were traditionally undertaken by its human workforce onto machines.

This has led to the advent of more complex set-ups, where large quantities of low latency data that has been acquired from sensing/monitoring devices is distributed throughout the system. Of course, the factory floor presents an extremely challenging environment for any form of electronic component that is incorporated into the equipment being utilized. In the following article we will look specifically at how it affects connectors.

Connectivity in industrial applications is a critical element and so the components providing this aspect need to be rugged enough to function accordingly. In this context there is the potential for ongoing exposure to elevated temperatures, heavy shocks or strong vibrational forces. If any of these were to cause a cessation in connectivity that resulted in either the power or the data no longer being transported through the system as anticipated, then severe financial penalties may be accrued as a consequence. Manufacturing production lines could be halted for a prolonged period while the fault is identified and the component responsible located then subsequently replaced. The faulty component may be positioned somewhere that is very difficult to reach, which will further complicate matters.

Downtime relating to the ensuing repair work can have a significant impact on production output. In industrial processing plants, the implications could be even more serious. Here, there is the prospect that component failure could possibly put lives at risk. Due consideration should thus be given to the numerous different factors that could impinge upon a connector’s functional integrity.

Another issue to be aware of is that in industrial infrastructure there are often acute space limitations to contend with - leaving very little room available in which to install electronic boards and circuitry. The migration to Industry 4.0/Industrial IoT (IIoT) means that higher levels of functionality will need to be built into automation systems, so that access can be gained to valuable information that will help to push efficiency levels upwards. In doing this, even greater pressures will be placed onto engineers - not only in terms of the board real-estate they have to work with, but also how closely these boards need to be stacked together.

With ever more sophisticated systems to deploy, but less and less room in which to deploy them, higher density arrangements need to be utilized. Not only will the constituent components have to fit into the confined space available, but they should also not create an obstacle that impinges on the system’s thermal management activities (by obstructing the airflow passing over the boards on which they are situated). Though 2mm pitch connectors were quite acceptable a few years back, now lower profile connectors with much narrower pitches are being mandated. A durable plastic construction is normally recommended to maximize mechanical robustness and it almost goes without saying that a wide working temperature range will also be considered obligatory.

In such space constrained settings, often blind mating will be unavoidable, so the interconnection technology must also accommodate this feature, as it is vital to avoid the occurrence of mis-mating (and the damage that this can entail).

The connector should also possess the insulation capabilities to cope with the industrial voltage demands and the occasional exceptional load from voltage spikes. Though some connectors may be located in hard-to-reach places, others may be openly accessible – if this is combined with the need to test or reconfigure systems on a regular basis, support for multiple mating cycles becomes important and must be taken into account.

Finding an optimal solution that meets both the robustness and compactness requirements of such applications can be difficult, and in most cases will call for compromises to be made. Engineers are facing the need to rely on connectors with miniaturized form factors that manage to pack in more contacts, yet that still handle the environmental conditions that could shorten the lifespan of these components. Fundamental production practicalities mean that they must also support automated assembly procedures.

Engineers have a few possible options to consider. Firstly they could settle on specifying a standard performance off-the-shelf product. Admittedly this will help to keep the investment involved to a minimum. Moreover, such an approach will be relatively quick and simple to undertake. It does, however, mean that they could end up taking a big risk of failure, as there is no certainty that the chosen connector will be able to actually cope in the long term with the operational demands.

A second alternative is to implement a high-reliability connector (as used in military or aerospace applications), though understandably this will lead to greater unit costs. Another option is to go down the custom route. The outcome would be a connector solution that is highly suited to the system in question, but will again be accompanied by hefty financial outlay, as well as taking up considerable time and engineering effort. It should be noted too that, if the system requirements change in the future and the custom-built connector is no longer appropriate, then all this previous work will be wasted and need to be redone. In summary none of these choices comes without some associated drawbacks.

In order to more fully address the criteria that have been outlined previously, the experienced technical team at Harwin determined that a new series of board-to-board connectors was required. This range would attend to the need for high density installations with an improved feature set over the existing PCB connector portfolio. The result of this project was the introduction of the Archer Kontrol product offering.

Suited to a broad array of heavy industrial tasks, these space-saving, 1.27mm pitch interconnect solutions exhibit a high degree of mechanical robustness, while at the same time delivering substantial flexibility. They have a current rating of 1.2A per contact, and a choice of 12, 16, 20, 26, 40, 50, 68 or 80 pin versions for edge-to-edge, parallel board-to-board or right-angle mother-to-daughterboard orientations. An extensive variety of different stacking heights are available for design flexibility, so that boards can be stacked together at spacings that are suitable for the rest of the equipment layoutThanks to their fully shrouded design, these connectors have strong resilience to vibration and other mechanical forces, while polarization of the shroud and generous lead-in chamfers facilitate blind mating procedures. They support 500 mating/un-mating cycles, possess an insulation resistance of 1000MΩ (minimum), can deal with 500V AC and have a working temperature range that spans from -55°C to +125°C. Supplied in a tape and reel format, these surface mount components are, in addition, well suited to use with pick-and-place machines.

Author details: Wendy Jane Preston is a Technical Marketing Engineer with Harwin