Control System Upgrade
A local candy company had a depositing line that needed to be upgraded. The line was controlled by three servo drives controlled by an Allen-Bradley 1394-GMC controller, and the depositor had four servo drives controlled by a second 1394-GMC controller. Supervisory control and interfacing to the rest of the plant was done by a SLC-5/04 plc. While we could still support the 1394 controller and program in the GML language, the components themselves were obsolete and becoming extremely difficult to replace. The risk of total shut down due to failed components was becoming more likely every day. In addition, with a door safety switch on every door and multiple emergency stops the dual string safety circuit was complex and prone to problems. The line experienced significant down time due to safety issues as well as issues in the original program re-synchronizing the line motors after mold jams.
We upgraded the entire system. Replacing the SLC-5/04 with a safety rated CompactLogix plc with integrated motion communicating to Kinetics 5500 servodrives across ethernet. We wired all of the door switches and emergency stops into safety IO on the ethernet-IP network. The upgraded system provided much better feedback on status of safety switches, reducing troubleshooting required. It also provides for smoother restarts after mold jams.
