John Young, Chief engineer from Roberts PolyPro, after years of using a PLC solution with proprietary networks, needed to replace this by an industry open network. He looked for a more efficient and up to date automation solution for a new high speed French fry scoop (carton) maker that would run at 1,800 ft/minute, or 260,000 scoops per hour.
Previous designs had used one brand of PLC and another brand of drives, interfaced together by I/O. The HMI and PLC were connected together by the PLC vendor's proprietary network and I/O.
After discussion with CCA he decided on a solution using a Siemens S7-300 PLC and MM440 AC Drives networked using PROFIBUS. A TP270 touchpanel was incorporated for process setup and visualization.
John says, "By using standard motors and vector drives we had a lower cost, off the shelf solution, which gave significantly improved machine performance and maintenance. The PROFIBUS network also eliminated costly and troublesome wiring." Machine setup was significantly improved using recipe capabilities passed over PROFIBUS.
Larry Matson, Director of Engineering, says, "We had higher line speeds and were able to optimize machine efficiency by maintaining ratios between the drives through to full line speeds - and we attribute that to the high speed communications of PROFIBUS and the overall system architecture."Results were so positive that Roberts PolyPro is looking at using PROFIBUS as a standard on upcoming machinery.