You just put some materials in, mix them up, maybe do some filtration and package it. It might not even seem worth automating, until a top-tier customer spending $300,000 a month says they want you to. That was the situation at a DuPont facility in California, making electronics cleaning solutions that are so special, they can’t be named.
“It’s a formulation process that looks simple but is surprisingly complex, done almost entirely manually,” said Nancy Givens, P.E., automation and process control engineering consultant, DuPont. “It had a semi-automatic mode but it was rarely used because the operators didn’t trust it.”
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Givens presented the session, “DuPont Migration and Batch Automation Using Rockwell Automation FactoryTalk Batch, eProcedure and Material Manager” at the Rockwell Automation Process Solutions User Group (PSUG) meeting this week in Houston.
At DuPont, she provides consulting services to support process improvement, operator training simulators, process monitoring, and capital projects. Her expertise includes batch automation, systems integration, plant commissioning and startup, wireless instrumentation, and wireless/mobile applications for manufacturing & process control.
The facility was running a Rockwell Automation PLC-5/60 with an Intellution HMI. The hardware and software were obsolete and no longer supported. The legacy system was “way past Silver Series, with pop-up screens galore that didn’t disappear automatically, so there was a lot of clutter with high potential for human error,” Givens said.
Alarm setpoints were a mix of user-editable and hardcoded, which were difficult to maintain. “It was done way before ISA 101 or 82, and there was no way to assign alarm priorities,” Givens said.
Time to move up
One of the reasons the plant replaced the system was the risk of losing the business of that important customer. Preventing that meant improving quality control through recipe-based automation. Another reason was to increase production on a sold-out product, a $1 million per month potential that could be met with through unit coordination.
The project was planned in phases. Phase 1 was to upgrade the HMI and PLC to a Rockwell Automation PlantPAx DCS, keeping similar functionality but with improvements. Phase 2 added FactoryTalk Batch, eProcedure and Material Manager for full recipe and sequential automation. A later improvement modified FactoryTalk Batch for unit coordination.
But there were challenges. For one, “The plant’s favorite system integrator (SI), TechKnowsion, had no experience with FactoryTalk Batch, so we needed to bring them along,” Givens said.
DuPont has done similar batching upgrades elsewhere and wants to leverage work from other sites, so it wanted to get DuPont Engineering or a business subject matter expert (SME) involved early. Givens was the SME on this project.
They decided to use the system integrator for phase 1 work, and to use Rockwell Automation and the SI in tandem for phase 2. Rockwell Automation provided the FactoryTalk Batch knowledge to train the SI, and the SI built repeat instances and learned the application for long-term support.
Givens was involved in all phases to train the SI on DuPont library for HMI/controller objects in phase 1, and to ensure leveragability in phase 2 from similar batch upgrades.
In detail, the functional requirement specification (FRS) was done with Rockwell Automation and TechKnowsion; detailed design by DuPont, Rockwell Automation and TechKnowsion; configuration 60% Rockwell/40% TechKnowsion; and FAT by DuPont, Rockwell and TechKnowsion. The punch list was resolved by Rockwell Automation with testing by TechKnowsion; and site commissioning and startup involved DuPont, Rockwell Automation and TechKnowsion.
A second challenge came when they realized the SI had sized the controller based on regulatory control, and didn’t take into account the need to load phases, etc. “We’d put in an (ControlLogix) L71 and needed more, so we went all the way to an L75,” Givens said. “Our rep worked with Rockwell Automation and we were able to make an exchange. The lesson is, you need to have someone knowledgeable about the whole architecture there from the beginning.”
“TechKnowsion had critical knowledge but needed to learn from Rockwell,” Givens said. “In all phases, we involved the SI so they could know the whole process, which is important for long-term support, future expansions, and adding automation to the skids.”
Phase by phase
The phase 1 controller and HMI upgrade involved reverse engineering of PLC-5-based code to determine the requirements for new code. “We didn’t just convert the code,” Givens said. “We didn’t use a conversion module, we improved the code and cleaned it up.”
A PlantPAx-based DuPont library was used for control modules, and a gray-scale HMI includes alarm management capabilities with alarm setpoints and priorities set at the control module faceplate. “We followed ISA101 recommendations for HMI, and 18.2 for alarm management,” Givens said. “Now the displays are simple, gray-scaled, and use the DuPont library with PlantPAx graphics.”
Phase 2, batch automation, “started, finished and was executed as an S88 design, with strict separation of the physical and procedural model,” said Givens. “I kept reminding the plant that no individual operation is unique. It’s what you use—the chemical components—and what sequence of steps you put them through that is unique.”
“We thought all the unit operations would be class-based, but for some products that used filters, we needed instance-based,” Givens said. “We thought about tricking the system because it would be easier, but that could cause problems at a later date if someone tried to put a program on the wrong machine. It was a philosophy discussion we had to have, and decided to do more work as a project team for the long-term benefit of the plant.”
Modularized code promotes reuse and flexibility, and separate physical and procedural models provide flexibility. Automated phases in Phase Manager include material addition, routing, agitation and packaging. Addition phases are material-based to work with FactoryTalk Material Manager, and manual phases managed by FactoryTalk eProcedure, with prompts for sampling, recipe review, etc.
“We found we needed to run a timer over two units to track total time. We could have built controller-based timers and transferred the time from one controller to another, but that could get complex. Instead, we were able to configure it as a report parameter with just a few clicks using the inherent capabilities of FactoryTalk Batch.”
FactoryTalk eProcedure is used across DuPont in FactoryTalk Batch implementations. It provides a manual phase that smoothly integrates with automated phases, without a need for a controller-based phase. “eProcedure lets you create a recipe without knowing which steps are manual and which are automated,” Givens said. “That gives you more flexibility.”
Givens uses eProcedure View for operator interface, not FactoryTalk Batch View. “You can create instruction files using HTML, and data can be entered by the operator or using barcode scanner. Entries can be selected via button or dropdown, with display of parameterized information and live data.
This was the first DuPont use of FactoryTalk Material Manager. “Level readings in the storage tanks are not accurate, and the plant was not interested in investing in better level technology,” Givens said.
The site maintains a paper log of storage tank inputs/outputs to track inventory. FactoryTalk Material Manager will make this electronic and provide other benefits of automation, including tracking and reporting of materials and lots, automatic tank switching, and material-based addition phases (not equipment-based). It can also be used for manual charges and tanker offloads.
Commissioning, startup and results
Servers were staged in a conference room, factory acceptance test was completed and startup was performed on a weekend. Production turned the system over on Saturday at 2 pm, then HMI alarm and history databases were migrated to image, and the images were replicated to the correct primary server. On Sunday, they installed and started the servers, and checked out all services and connections. Production started at 4 pm Sunday. “We did two-shift coverage for the next week—we were right with them, got their comments and made improvements.”
The new system is fully supported, provides alarm management, and has a calm, gray-scale HMI for less risk of human error. Alarm setpoints and priorities are in the control modules. The controller programming is ladder and function block—well organized and clean. Batches are fully automated, including cleaning, and reported through SQL reporting services.
On reflection, for the dual execution strategy, Givens advises having one subcontractor report to the other for a chain of responsibility. Require vendors to use recommended software/versions. Review all recipe designs to ensure accuracy of steps and timing. “This is best done by the end user and not the vendor,” Givens said. And require early configuration reviews to discover problems before they are throughout the software. “Sequential function chart programming is not like ladder logic.”
In conclusion, Givens acknowledged contributions by Robin Lopez at DuPont, Gregory Arevalo and Omar Ponce at TechKnowsion, and Tom Branch and Alex Bollas at Rockwell Automation.
