Phased modernisation offers time and cost savings
A phased control system modernisation solution for a production line has offered a better return on investment for one castings Manufacturer. Control Engineering Europe reports.
US-based American Castings has been in the metal casting business for over 100 years, producing everything from front and rear axles to backhoe booms for its agriculture, mining, and oil & gas customer base.
A need to increase production levels, led the company to consider upgrading its No Bake production line control system – a SY/MAX PLC with one processor and 10 remote I/O racks with around about 1,000 I/O.
The system is designed to transfer metal castings that weigh up to 15 tons. The metal is poured into moulds which move along a conveyor to help the metal solidify. Once that process is complete, the castings are shaken and shot-blasted to remove the sand mould and expose the solid metal.
The company was encountering slow scan time, which resulted cycle issues in the production line and in the DOS-based software. Trying to find older computers that could run the software and had appropriate communication ports posed the company with another issue.
American Castings knew it had to update its system, but one option didn’t sound so appealing. Darryl MacKay, maintenance systems manager at American Castings takes up the story: “We could have replaced the entire system – that would have led to major downtime and the outage of the line so we could convert all 10 remote racks and the logic to run the production line.”
Finding a better way?
Instead, the company found a way to minimise its upgrade risk and costs by being able to keep the existing SY/MAX I/O – even after it switched to a Rockwell Automation ControlLogix system.
By using an EtherNet/IP to Square D Remote I/O Gateway from ProSoft Technology, the company was able to retain the existing SY/MAX I/O – and run the new and legacy systems in parallel, making sure they could troubleshoot any initial bugs in the new system while production kept up via the legacy setup.
Switching processors while keeping production running on the older SY/MAX network helped the company avoid the major downtime tied to a traditional rip-and-replace modernisation project. Two Americal Castings employees – Roger Gibson, automation engineer, and Jerrod Estes, automation specialist – reviewed the gateway at an automation fair and researched it to make sure it would work in the application.
With the gateway, the ControlLogix is able to control the SY/MAX I/O. In the long-term, the company is planning to replace the remote racks, but this phased modernisation has enabled it to do the work on a timetable that better suits its business goals.
The time and cost savings gained in opting for a phased modernisation were sizable. Gibson estimated that the company saved about 100 hours by eliminating the need to rewire all of the I/O racks, and 40 hours of troubleshooting to make sure the system would work, since they were able to run the systems in parallel and not lose valuable production time. He projected the cost savings at nearly 82,000 euros in lost production and implementation time.
In addition to meeting the company’s goals of upgrading its controller, standardising the control programme, and decreasing the upgrade costs and risk by keeping the legacy I/O, American Castings was able to achieve the following improvements:
• Recipe-driven mould-making, which will enable better follow-through of process control, faster scan time for better reaction from the line, and tightened conveyor movements.
• Errors caused by slow scan/response times have been eliminated.
• Management can get operational data more easily.
Source: Control Engineering Europe - All Articles