Where are automation trends leading programmable logic controller(PLC) and human-machine interface (HMI) solutions? The two are moving together, and becoming more tightly integrated, according to Richard Harwell, advanced solutions manager with Eaton. And in the process, I/O wiring, components and resources--from commissioning to long-term maintenance efforts--are going away. His stance on the issue was the same as the title of his presentation at the Pack Expo 2013 Innovation Stage: "The Heart of a 'Lean Automation' Solution: Integrated HMI & PLC."
As PC and PLC automation architectures begin to merge into a common box that can also host software and connectivity smarts, he sees "Lean automation' as a solution, or minset that will translate much more than control solutions with fewer components: "It's the idea that it's faster to develop, it's faster to build, and it's easier to administer," he said, as well as provides more value in the long-term, or the full lifecycle of a machine. He stresses the notion of communication over control and visualization, because communication is the "third leg of the automation stool."
"By having smarter devices that give you more diagnostic information," Harwell said, adding, "you can increase your uptime." Additionally, security benefits from tighter integration and fewer IT resources (open ports, multiple ports open, etc.)
The premise of merging the HMI and PLC platform is that there has been an increasing functional overlap in areas such as security, alarms and enterprise-level Ethernet. (See figure.) Of course, when merging platforms, Harwell noted, "It's really critical that when you marry these two platforms you really need to make sure that the performance is there--first and foremost the logic processing cannot be compromised. But you can't overlook that the screen graphic changes are fast and meet operator interface needs."
Speaking on the lean aspects of connectivity, Harwell noted that at the device level, connectivity benefits of an integrated HMI and PLC include the replacement of discrete wiring with smart cabling; the elimination of I/O wiring and cards in the PLC, reducing resources, time and cost.
