Mitsubishi A to Q Series Conversion Case Study

Project Summary

A large metal processing facility was using aging Mitsubishi PLCs. Patti Engineering upgraded those PLCs, paving the way for system upgrades now and in the future.

Challenge

A large metal processing facility had multiple Mitsubishi A series PLCs throughout the facility. This PLC is no longer made and is no longer supported by Mitsubishi. Replacement parts are becoming increasingly difficult to find. Concerned that eventually the search for a replacement I/O card or spare part would cause significant downtime, the facility decided to proactively convert to Mitsubishi Q series PLCs. They also decided to make some upgrades to the system, which the new PLCs would allow.

Solution

The first location where the PLCs were converted was on carts that move the coils of metal from production to a temporary storing facility. The PLC on each cart communicates with the panel to sort the coil to the correct storing location. Both the PLC on the cart and the PLC on the panel was upgraded from Mitsubishi A series to Q series.

In addition, the old system used optical communication, which uses light instead of radio, to communicate between the cart and the panel w. It was originally installed nearly 30 years ago. This was upgraded to wireless communication using TCP IP Communication, a technology that is much more common today. To improve the speed of data transfer, we added an L series PLC to communicate through PCP IP and to be a bridge between the two Q series PLCs on the cart and panel. This addition decreased the cycle time from every 100 milliseconds to every 1 millisecond.

Each of the cart upgrades were completed in 1.5 – 3 days, minimizing downtime. By completing each of the carts separately, workarounds were easily implemented and kept production running.

Benefits

The most obvious benefit to the customer is a more reliable system, and no more sleepless nights wondering if eBay will have a part if something breaks. In addition, the newer system has increased capability, allowing for additional system improvements down the line. The Q series PLCs have faster processing and can handle more data and newer, more efficient equipment. For example, it can handle nearly any VFD (variable frequency drive) on the market.

After seeing the benefits of upgrading the carts just over a year ago, we have already worked with the company to convert four other areas of the facility from Mitsubishi A series to Mitsubishi Q series.