Building blocks for the packaging industry
Modular automation pays off

What has long been practised in mechanical engineering is now also becoming part and parcel of automation and control software: standardization through modular systems. The challenge that faces the pharmaceutical industry is how to reduce the complexity of control software while at the same time taking into consideration the validation requirements of developers.

Many machine manufacturers have gone over to giving the mechanisms of their packaging machinery a modular design so that, once developed and tested, modules can be used time and again at little modification expense. A modular or building-block system developed in this way offers enormous time advantages and cost savings.

The definition of a modular system requires considerable concept work. The machine modules are self-contained functional units with defined interfaces. They can be swapped without affecting other constructional units of the machine. Modules may, for instance, include mechanical, pneumatic and electric elements and of course control functionality such as logic control, motion control or technology functions (e.g. temperature control). There are at present two fundamental topology structures for modular automation. The first is more suitable for compact machinery with a central control. Here, the automation functionality of the machine is defined as early as in the engineering phase. The control programs for motion control, logic control and technology, the user interface and the relevant hardware configuration of the machines are composed of tested modules of a library of modules.
Intelligent modules
The basic program in the control is identical in all versions of the machine. Depending on the machine options used, program modules are added and the user interface is simply complemented by the corresponding screen components.
The second topology variant relates to an automation group with mechatronic functional units. Here the modularization is taken a logical step further, exploiting the capabilities supplied by modern communication mechanisms and component-based automation.
The modules have their own intelligence systems and are linked to each other by means of defined interfaces. The functionality of the modules is encapsulated in the interior of the module software. The advantages are obvious: individual modules can be developed independently of each other, any module can be extended, and the changes have very little impact on the machine as a whole. Modules can be exchanged without influencing neighbouring areas of the machine and multifunctional communication interfaces reduce wiring requirements. So what does this mean? Clearly defined modifications to the machine limit the cost of revalidation, if indeed any such cost arises. That in turn delivers shorter commissioning processes, less risk and lower costs.
Modular automation
In Simotion, Siemens offers a motion control system that meets the requirements of modular production machinery. The embedded functions for modular automation make the development of modular machines particularly easy, supporting:
-tested library elements for control systems and
-lectronic type plates for the automatic identification of components in the system.
What is more, when combined with the WinCC flexible visualization system it is almost child’s play to generate the complete motion control, control unit, technology and visualization functionality. WinCC flexible permits the definition of graphic elements (known as faceplates), including the associated control variables, which can then be stored in libraries and used in several other projects.
WinCC flexible also offers optimal support in the creation and operation of systems and subsystems with its “Change Control” and “Audit” options. The “Change Control” option allows engineering functions to be covered, including:
-access control and user management through automatic ageing of passwords;
-versioning of configuration through complete reproducibility (roll-back function), something that is enormously helpful in the test phase in particular.
The “Audit” option enables every operator intervention in ongoing operation to be tracked and logged and then sent to higher-order systems for long-term archiving as protection against manipulation. Specific operations requiring confirmation by qualified personnel can be sealed with an electronic signature. Concrete information for the project designer with regard to the satisfaction of Norm 21 CFR Part 11 requirements has already been included.
Standards for flexibility
The openness of the system and the use of communication standards also ensure the optimal integration of the machines in the user’s specific automation environment. Profinet, the cross-manufacturer Ethernet standard for distributed automation, is gaining increasing significance in this area. Profinet enables all major themes for industrial automation to be covered, including real-time communication (as the basis e.g. for distributed synchronization) as well as important functions such as network management.
In short, then, a package consisting of control, visualization and communication offering many inbuilt features that cuts the development costs of OEMs involved in the pharmaceutical industry.