Replacing or upgrading old control systems is usually done with sombre deliberation. In the case of the Moore DCS application upgrades at ArcelorMittal South Africa’s Pretoria plant, however, things were decidedly rosier as a result of using Wonderware technology.
Since the Moore DCS is classified as a ‘mature’ product, the only option for companies using the legacy and often equally mature applications linked to the DCS is to upgrade to more contemporary solutions that meet today’s industrial automation needs. Upgrading such a system includes preserving the initial investment as much as possible while also providing a path for growth, versatility, integration with other applications and the freedom to choose the best hardware and software solutions to meet new challenges.
At ArcelorMittal South Africa, two Moore DCS application upgrades were in the pipeline and starting from scratch seemed a less-than-desirable option. ArcelorMittal South Africa was keen to have a lower cost and more risk-free alternative and decided to get the opinion of ArchestrA-certified system integrator, Control Systems Integration who had already performed three Moore DCS application upgrades.
System considerations
“When handling such an upgrade, several things have to be considered,” says Dries van Schalkwyk of Control Systems Integration. “For example, can Moore’s ProcessSuite Vision application be converted to the proposed human-machine interface or HMI (in this case, Wonderware’s InTouch 9.5)? The first time one runs such a conversion, a large number of errors with regard to OCXs, DLLs and other things are reported (this includes the custom OCXs and DLLs developed by Moore). The next consideration is the communication to the DCS. Then there are the questions about converting to the Ethernet protocol and many more.”
The upgrades at ArcelorMittal South Africa included replacing Moore’s APACS ProcessSuite Vision application and a FIX32 application, both of which were connected to the Moore DCSs.
Replacing the Vision application
When evaluating the possible use of InTouch 9.5 to upgrade the Vision applications, CSI identified the essential DLLs as well as those DLLs that were not required. Similarly, two essential OCXs were identified before a batch file was developed for the copying and registration of OCXs as well as a lengthy list of wizards. For testing purposes, the same I/O drivers as used by Vision were used for InTouch.
“For all intents and purposes, Vision is actually InTouch 7.11 and so the upgrade to InTouch 9.5 is well understood,” says van Schalkwyk. “The first successful upgrade took about two weeks, but subsequently, we completed two different applications in about 15 minutes each. So, moving Moore DCS Vision applications to InTouch 9.5 is fairly painless and quick and there is no redefinition of graphics or re-commissioning required.”
Benefits
* Low cost – No changes to the existing graphics are required and, since Vision runs on InTouch 7.11 licences, these can simply be upgraded to InTouch 9.5. The same holds true for the historian.
* Low risk – No re-commissioning required.
* Quick – Once the pre-work is done it takes only about 15 minutes to upgrade an application.
* Flexibility – With the appropriate driver, InTouch 9.5 caters can connect to any PLC.
* Freedom of choice – End users can decide for themselves what will replace the Moore DCS and are not locked in to one technology.
Replacing the HMI application
This was being used in two different areas of the plant with old ProcessSuite licences and no Vision applications. The I/O server was built into the FIX32 application, which meant that a new I/O server was required. The scada PCs all had ISA ModuleBus interface cards and Control Systems Integration planned to replace the communication to the DCS with the Siemens Internet Ethernet Module (IEM).
“This project looked a good candidate for ArchestrA and we selected two redundant application object servers (AOS)”, says van Schalkwyk. “They were each located in different areas of the plant and connected with a redundant fibre link.”
Benefits
* Lower cost (for the HMI portion) – Once more this involves an upgrade of licences and, if more applications are involved, end-users can expect to make significant savings on engineering costs once the ArchestrA templates have been defined (the Moore DCS lends itself well to the auto-addressing templates in ArchestrA).
* Re-use of engineering – Graphics could be re-used while objects can be replaced with Smart Symbols.
* Low risk – Once the ArchestrA templates have been implemented, the rest is done with auto-addressing and the chances of errors are minimal.
* Flexibility – The ability to connect to any PC or other devices through the use of the relevant drivers.
* Freedom of choice – ArchestrA leaves the choice of future hardware and software solutions to the end user.
* Versatile communication – through access to Microsoft’s .NET communication framework.
Conclusion
“Most of the problems encountered with such upgrades have to do with communication architecture and components,” adds van Schalkwyk. “Two of the three customers who approached us for upgrading their Moore DCS installations mentioned that some system integrators said that this was impossible. Do not believe such claims of impossibility. We have proved that it is not only possible but also fairly easy. Possibly the best thing is to prove it to yourselves with a thin slice implementation.”
For more information contact Dries van Schalkwyk, Control Systems Integration, +27 (0)12 667 4646, [email protected], www.controlsi.co.za or Justin Tweedie, Wonderware Southern Africa, 0861 WONDER, [email protected], www.wonderware.co.za
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