The PCS 7/90 OS HMI system is configured to notify operators of critical events by dialing directly to their ordinary cell phones. When alerted, operators can view the exact same screens remotely on laptop PCs as those that are displayed on the HMI consoles at the plant.
“One of the biggest benefits of moving from the legacy consoles to Windows-based PCs is not having to work with older-generation machines,” Berry explained. “Our previous vendor’s control system software is not compatible with today’s standard desktop computers. Now we benefit from the higher speeds, Windows-based security and report generation. In a pinch we could go to the local store to acquire a replacement PC, rather than searching to find old compatible machines.”
“The software that we had would only run on out-of-date PCs. I can only run them on machines that were slower than 133 MHz. I couldn’t buy those machines anymore.” Air Products had to stockpile obsolete computers to use as spares. Migrating to the new HMI system will ease the maintenance burden by minimizing the number of obsolete systems to be managed.
Because Orlando was a test site and the Siemens PCS 7/90 OS HMI was in the prototype stage, both companies took the time to work together to develop a solution that easily could be replicated with low risk at any of the 100 Air Products plants with this particular legacy control system, added Berry.
“Siemens invested a lot of time to develop the product in collaboration with us,” Berry said. “They did a lot of the engineering. The development exercises produced libraries, faceplates and templates. Now there is an existing library of elements from which we can pull information. Future upgrades will take advantage of this work and enjoy minimal re-engineering.”
A different driver
Halfway through the Orlando HMI upgrade, a similar large air-separation unit in Ghent, Belgium, was beginning a comparable transition from the same legacy HMI operating system to Siemens PCS 7/90 OS HMI. While one of the main drivers for the Orlando plant was remote connectivity, the Ghent plant had another priority — adding production capacity. At the time, a second large air-separation unit that would utilize a full PCS 7 architecture including control and I/O was being built at an adjacent site at Ghent. The goal was to introduce a platform that would run both the old and new units from one control room using a common HMI system. Berry said much of the information gathered at the Orlando beta site was shared with engineers working on the Ghent installation.
“Ghent learned from Orlando and Orlando learned from Ghent,” Berry noted. “We kept the controller hardware, input/output modules and field wiring from the legacy system.
A common terminal bus for HMI connectivity allowed us to share everything else between the legacy system and the new PCS 7 system — including clients and remote access.”
Now that both the Orlando and Ghent installations are operating, Berry said the robustness of the systems has improved. They have been running for months with no HMI related outage. He said diagnostics are clean. Parameters are good.
“Our beta site at the Orlando plant proved we have established a solid HMI migration path for multiple platforms by standardizing on Siemens PCS 7 HMI technology,” noted Berry.
“One of the unique things about the Siemens architecture for migration is that the core engineering tools and everything above it (the HMI layer) are the same for each different control platform,” he added. “DCS-specific software plug-ins enable this and should make our work force more productive as we won’t have to rely on as many specialists.” Once the database is converted from any platform, the HMI work is the same across platforms from any vendor.
Berry said he now has the commonality in the HMI hardware, software and tool sets he was looking for to perform plant upgrades in the Americas and Asia. The Air Products controls team can work with a variety of HMI tools that they can carry over from one site to another, boosting their productivity and enabling them to more effectively handle the large number of plants.
Today, Air Products’ HMI replacement strategy is well underway. Plants in North America and worldwide are taking advantage of the clear migration path that is minimizing operating platforms and reducing costs, according to Berry. The end result will be increased operator confidence and maximized global HMI commonality, he said.
Todd Stauffer is PCS 7 Product Manager for Siemens Energy & Automation, Spring House, PA. E-mail him at firstname.lastname@example.org.