Layered distributed control
To address the different circumstances the team faced, NACI employed a unique architecture that enabled separate control systems to function together and also laid a foundation for E66’s data acquisition goals.
At the top level, NACI used a groov EPIC (edge programmable industrial controller) to establish a primary control network. EPICs combine PLC control with embedded HMI, OPC UA, and secure gateway server functions. The EPIC supervised the process lines, connected disparate devices through REST APIs, and integrated any equipment that arrived with a defunct control system as simple remote I/O.
Any functional controllers, on the other hand, were left in place and loosely coupled to the main process using groov RIO edge I/O modules. These modules provide software-configurable, multi-signal I/O channels, and are powered over Ethernet, making them quick to deploy. Upon arrival, NACI placed a module in each piece of equipment, connected any I/O wires, and identified the types of signals the equipment provided. These I/O signals were then integrated into the groov EPIC network in parallel with the existing PLC I/O connections, which continued to function independently.
Coombs noted, “The ease with which you can do this—you’re talking about a half-hour of wiring. Your biggest problem is finding the documentation from the original manufacturer.”
NACI also engineered an additional layer of control independent of the groov EPIC by building limited local control into each groov RIO module through Node-Red, an embedded, open-source IoT platform from IBM. Living up to the ambition to make every device smart, NACI added motors, photo eyes, load cells, and other instrumentation to many pieces of semi-automated and dumb equipment, connected these to local groov RIO modules, and added Node-Red logic to make them work together and report process data up to the supervisory level.
E66 Chief Operating Officer Robert Bodnar explained, “The top-level process [in the EPIC] is turning on two lines or three lines. If you have a line coming in and you have a line going out, they may not be running at the same speed…so it’s kinda neat to be able to say, okay, what if we use the groov RIOs to control just the lines and the belt and case packers and things like that?”
This loosely coupled, distributed architecture allowed NACI to assemble its production line without modifying any of the existing control systems that came as part of their purchased equipment. This strategy ultimately saved them development time, and, in three months, Coombs and his team had 15 pieces of equipment up and running.
But this wouldn’t be their last challenge.