Safety can now pay its way!
Arguably, information is the most powerful tool in manufacturing today, with data being made available from the component to enterprise level and converted into information-enabled management tools. But, what effect is this having on machine safety?
Traditionally, safety has been considered to be a necessary evil – and was often seen as a hindrance to productivity. However, thanks to developments in products, industrial communication protocols and Ethernet networking capabilities, safety has become a more integral part of manufacturing control solutions and effectively coexists on the same network as that used by the automation, process and motion control architectures. Holistic safety practices – including those that incorporate tighter integration with existing control architectures – regularly demonstrate a positive effect on the bottom line and play a huge role in the general wellbeing of the plant, the machines and the employees that operate them.
Today’s Smart safety solutions which embrace the Industrial Internet of Things (IIoT), can now even help to optimise plant operations.
Safety products can now provide additional operational data which is outside the bounds of that already being collected. Using this information it is possible to gain a real-time understanding of worker behaviour, machinery compliance, product degradation, the causes of safety shutdowns or stoppages, safety anomalies and, of course, any trends that result from this data.
Actionable manufacturing data on machine performance normally comprises factors such as speed and throughput, with safety systems traditionally delivering stop/go or safe/unsafe signals. But with today’s intelligent smart safety devices, it has become much more than this. It is the delivery of intelligence, based on usage, life, degradation and performance drops. And with this additional data, coupled to that already being collected, the possibilities to optimise operations increase exponentially.
Operator behaviour can have a big effect on the output of a machine. Operators will always try to make their life easier and will find ways of circumventing procedures to speed up or simplify their day-to-day job. To this end, safety system interactions can be logged to see when an operator is deliberately stopping a line or triggering a safety device. These actions can then be analysed to show trends which can be used to ascertain the reasons behind those triggers. These trends can highlight shift variances too. If an E-Stop is used more on the night shift than the day shift, does this mean there is an issue with the machine or the operator? Is better lighting needed, or is more training required? These things can be ascertained effectively through a smart safety system.
Product degradation and obsolescence is another important factor, especially when it comes to determining maintenance and replacement programmes. Before the advent of Smart safety solutions, operating parameters, such as mean time between failure (MTBF), would be documented manually and any changes in operating procedures would require recalculation and re-documentation. With a smart, connected, integrated system, users are now able to formulate predictive maintenance based specifically on exact usage, using figures generated by the smart device. These new figures can then be used as part of a more precise and more representative life calculation.
Degradation doesn’t just mean ultimate failure, it could be something as simple as a safety light curtain getting dirty, reducing its effectiveness. Smart devices can timestamp when issues occur and machine logic can then be exploited to deploy the necessary remedial action before it affects the line’s performance. HMIs or mobile devices can display suggested maintenance procedures and share this data with the top floor to see if any procedural changes can be made to prevent them happening in the first place.
The IIoT has given users access to the right information, in the right format at the right time. For example, a maintenance engineer with a tablet can exploit position beacons along a line or machine to interrogate specific safety equipment in precise locations, receiving the data as he approaches each area, dynamically without having to request it manually. The same is true for an operations manager, who would use the same software on the same tablet and the same location beacons, but receive information applicable to his or her credentials. Using these core tools and technologies helps give contextualised information to the individuals need, based on their function or job.
In instances where EtherNet/IP capability is not on the device, users can exploit newer intelligent device-level linking technology such as Rockwell Automation’s GuardLink protocol, which can feed individual device information back to a host controller. GuardLink is a safety-based communications protocol, utilising standard cabling in a trunk and drop topology with plug-and-play connections. It can reduce wiring, while providing device location and delivering diagnostics, remote reset and lock commands over a single cable. Traditional safety solutions are hard wired in series, so in operation, the user may lose the ability to distinguish the demands of individual devices; and if a component fails, the user is only aware that a component somewhere on the series connection has issues. Individual connections to each individual component requires significantly more wiring and introduces many more potential fault points that can lead to unnecessary, unplanned downtime. This also increases costs for machine builders.
Safety is no longer the burden it used to be and it no longer needs to be a discrete element in machines and plants. As an integrated system it can deliver multiple positive benefits, not just in terms of lowering engineering and design demands, but also in terms of its data capabilities and return on investment. Fully integrated safety solutions have already shown their worth and with the advent of greater connectivity and broader data sets, operators are getting more insight into their operations, allowing them to address, conquer and exceed a wider variety of operational metrics, while still delivering enhanced safety to their plant and personnel.
Source: Control Engineering Europe - All Articles