SCADA system migration

Transferring existing applications from one SCADA system to another tends to be associated with intensive engineering operations and thereby high costs. However, this is not the case if the procedure takes a methodological approach, if developers of the source and target system assume responsibility for the migration, and if this procedure is predominantly automated, thus ensuring a fast, smooth and consistently reliable transfer.
Tony Druery from Siemens Industry Automation advises users of common systems such as FactoryLink, how a SCADA system migration to a WinCC platform can be managed via a bespoke migration support service which can help businesses save time and cut potential migration expense by up to 50%. Critically, such a move opens the way to enhanced SCADA system benefits for current legacy system users that can only aid operational efficiency and competitive objectives.

Working with legacy systems can present a number of problems for companies.  Chief among these is the potential future issue around an inability to migrate to another system, or only being able to do so in costly expenditure and engineering manpower terms.  Other problems may arise from ongoing maintenance and upgrade viability, spare part availability, staff knowledge vacuums as key personnel depart with their system experience, or simply an inability to benefit from the operational efficiency benefits provided by more modern state-of-the-art systems.  While it may be tempting to adopt the status quo and stay with an existing legacy system, users of the legacy system such as FactoryLink should examine the clear benefits of a managed migration to newer platforms such as Simatic WinCC – a process that can be undertaken easily, speedily and cost effectively.

When Siemens AG took over the American software house UGS Corporation, now known as Siemens PLM Software, and incorporated it into its Industry Automation Division, it resulted in an overlap in terms of the functionality of the FactoryLink and Simatic WinCC SCADA systems. So the decision was made to stop developing FactoryLink, to transfer that product to "maintenance status", and to continue with the development of Simatic WinCC, which has been established  as Europe's leading SCADA system and had been specified around the world in countless applications across a wide variety of sectors.

However, in order to ensure that previous investments made in FactoryLink applications remain protected for years to come, a supportive and holistic support package for methodical migration to the latest WinCC Version 7.0 has been developed to allow users in all sectors to gain the tangible benefits migration could bring – without extensive cost and time implications.

The  FactoryLink Migration Service is based on the combined system and application know-how of the developers of both widely-used products and is supported by a migration tool which contains automated functions that can be parameterised on an individual basis.

The service is not restricted to simply converting process pictures and graphics, as is often the case with other tools. Nor is it a covert reconfiguration of the entire application. Rather, the support package ensures that the visualisation features (including all animations) are retained, along with all the functionality of the original SCADA solution, and that when the application is restarted it runs as reliably and is as stable as before.

It may be helpful to illustrate how the migration works in practice….

Every migration project starts with SCADA specialists analysing the existing FactoryLink application at no cost to the user.  The customer then receives a precise breakdown of all the necessary work, as well as a detailed assessment of any modifications which will subsequently need to be carried out manually. Since large parts of the basic migration process are fully automated, the risk of errors occurring is drastically reduced as compared to a purely manual conversion procedure. This also means that timings and costs can be calculated with confidence for all phases of the project.

Basic migration usually includes the conversion of graphics, animations and symbols, branches, ActiveX Controls, and scripts of the FactoryLink clients, as well as of internal tags and I/O Tags, alarms, logs, recipes, and timers on the server side. In short, automatic basic migration involves porting the most important key components of a FactoryLink  – and as such plays a significant role in minimising the engineering effort which needs to be expended on the conversion. Adopting this automated method over a purely manual approach usually enables companies to achieve a saving of well over 50% on a migration project.

The service is based upon a high degree of sophistication and the quality of the automatic conversion process, even where very complex process pictures are concerned, including all dynamic actions and animations such as color changes, levels, etc. The migration tool is capable of converting Client Builder graphics (CB, in FactoryLink Version 7 and higher), as well as ECS graphics from earlier versions, into WinCC format.
The automatic migration of server-side scripting procedures saves significant amounts of time and also excludes any possibility of human error, in the same way as the tool, which converts IML or CML scripts from FactoryLink into the Visual Basic Scripts (VBScripts) used in WinCC.

The functionality of the source and target scripts is practically identical, which makes future maintenance tasks much easier. The migration tool generates a log file for every completed script file (as it also does for every migration function), which records the corresponding status and any problems that may have occurred.

Basic migration is all that is required for simple applications and, once completed, the project is ready for a commissioning test run. However, with more complex systems additional manual modifications may be needed in order to unlock the full functional scope of the application.  The decision as to which migration steps will be carried out when is also entirely in the hands of the migration engineer, thus allowing him or her to act flexibly and to perform conversion work (or to have it performed by a third party) in line with the company's particular activities or budget.

Migrating older versions of FactoryLink applications to Simatic WinCC brings them right up to the state-of-the-art in terms of SCADA technology.  Any further developments made to the SCADA system will be gradually incorporated into the automatic conversion tool so it will always remain up to date. The basic functionality includes driver extensions for subordinate programmable logic controllers so no obstacles have to be overcome or unwieldy workarounds applied in this regard.

As migration projects which have been examined so far have shown, even very large and widely distributed FactoryLink applications (with Unlimited licenses) can be transferred easily, quickly, and reliably. In all cases, the WinCC license was more than adequate in terms of its size. This license has a maximum of 256,000 process data points (I/O tags), which are in addition to the internal tags processed (stored) in the SCADA system or derived from it.

However, the basic question of "why" remains; after all, "if it ain't broke, don't fix it", right? But what this much quoted adage does not take into consideration is that, by not converting a working system on principle, you are running the risk of eventually no longer being able to migrate to a later system, or only being able to do so at a very high cost and with a great deal of engineering effort.

By migrating a FactoryLink application at an early stage, the user will first and foremost obtain an up-to-the-minute SCADA system, along with all the benefits of Totally Integrated Automation in terms of uniform configuration and programming, data management and communication. Once migration is complete, the scalability, openness, and flexibility of the new system will also enable the addition of new SCADA functionalities as required.provide the very best conditions for easily adapting the SCADA functionalities to changing processes or for extending those functionalities by means of customized add ons or options from the comprehensive WinCC pool.

Migration also helps to ensure that the process and operational knowledge which has been built up over time and anchored in the system which operating personnel are already familiar with, is retained. With process pictures and operations transferred more or less 1:1   which is not the case with any reconfiguration project - the operating personnel should not require any additional training.


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