How machine manufacturers reduce complexity with the aid of modular HMI systems

The Lego principle is alive and well: increasingly, facilities in the (petro) chemical, pharmaceutical and food industry have a modular design. This way, process steps and machines can be combined as required, giving operators and planners a greater degree of flexibility. For example, a separation stage can be added in a facility to achieve new product characteristics, or, in the case of increased demand, modules such as mixers and dryers can be added. However, modular facilities are not only useful for process modification, but modularity also makes it much easier to engineer the entire system. Automation experts estimate engineering effort can be reduced by up to 70% by modular automation based on the MTP (module type package) approach. Also, facilities projects tend to use the EPC type of contract less and less, where one general contractor is responsible for engineering, procurement and construction. Instead, the trend is moving towards EPCM (Engineering, -Procurement and Construction Management), where the operator specifies the required facility equipment, which is then procured directly from the manufacturer. The EPCM contractor takes part in the process solely in a consulting function.

For the providers of machines and skid packages, this development first and foremost means much greater responsibility and a larger order size. At the centre of attention is now no longer the machine as an individual component, but its function, and the skid package that provides this function must be fully supplied, ready to run. This creates new demands for machine suppliers: in addition to machines for basic functions such as pumping, mixing or drying, they now also supply all peripheral devices such as measuring and controlling technology, as well as operating and monitoring devices. A machine manufacturer also has the same responsibility for these peripherals as for the core unit – regarding quality and reliability, conformity with all required regulations, country-specific certifications, warranty and service. Plant operators also increasingly want to use information from their systems for their own digitalisation projects, and this has to be supported by the installed sensor and automation technology.

A central requirement of the operating staff remains unchanged: being able to operate system modules on site. The key for this are modern human machine interfaces – operating and monitoring systems for monitoring and controlling machinery. Both intuitive and standardised user interfaces as well as security from unauthorised access are a must. The HMI also must be able to display data in the form of diagrams, tables or similar, and give the user a fast overview of the system status. The increasing digitalisation and integration of production processes produces a wealth of information.

Machine producers have additional requirements: they want to have small and lightweight components for their skid packages, easy to mount and integrate into the control technology of their customers. A key issue here is the simple storage and replacement parts management for the components. Because skid packages are delivered ready-to-run and have to operate on site usually without the support of the manufacturer, machine manufacturers want HMIs that are durable and reliable.

As if that was not enough, industry-specific requirements must also be met: the pharmaceutical and food industry needs HMI who are easy to clean and meet the industry-specific regulations such as the Good Manufacturing Practice (GMP). And when it comes to the chemical and pharmaceutical industries, as well as other manufacturing processes such as painting systems, the combustible dusts present and solvents used could result in explosive atmospheres, which means that the operating systems frequently also have to meet explosion protection requirements.

R. STAHL has been addressing these issues for many years: having been active in safety technology for hazardous areas for almost a century, we naturally place a clear focus on explosion-protection requirements for our operating and monitoring systems. The latest development is our new ORCA device platform, certified according to ATEX for Europe, NEC for the USA, CEC for Canada, and according to IECEx. IECEx certification and testing documentation are the basis for many other international certifications such as PESO for India, CNEX for China, etc. In addition to these, conformity with all product standards applicable in the countries of installation are naturally also important, such as electromagnetic conformity (EMC) and radio standards, to name a few.

Regarding explosion-protection, we have paid particular attention to the requirements of machine manufacturers: unlike many other certified Zone 2 devices available on the market, which still require an Ex enclosure for operation, ORCA devices can be directly mounted and operated inside a machine. This saves money, because an additional Ex enclosure and mounting work can cost more than the original investment for the actual HMI. In the case of compact machines, the ORCA devices can simply be placed into a cut-out, but they can also be mounted inside an enclosure without any impact on the enclosure's Ex protection. For example, the HMI can be placed inside an enclosure on a supporting arm, or mounted inside a cabinet.

R. STAHL's modular approach for the HMIs is new: individual components of the ORCA devices, such as the electronics box or the display box, can be replaced separately. This is of particular advantage in terms of sustainability and future-proof investment. Unlike encapsulated devices which have to be returned to the manufacturer for repair, the modular ORCA devices can be replaced by the operator's staff themselves. Machine manufacturers can use the modular design to provide their customers with a fully pre-configured computing unit in the case of hardware updates or repairs. This saves time and money for both. This updatability guarantees a future-proof investment for a minimum of 15 years. Compared to classic operating systems, the modular design saves about half the investment costs during this time.