All three Goodman dual-head carton packers running at Planters operate as a single, synchronous machine because they’re electronically linked through an Allen-Bradley product called Flex I/O, from Rockwell Automation (Milwaukee, WI). No one appreciates the benefits more than Planters engineering manager Ted Brown.
“The cartoning system practically runs itself,” says Brown, “but it has to be very tightly controlled so none of the cartons slam into one another. Goodman did a very nice job on the logic.”
A single programmable logic controller, an Allen-Bradley SLC 5/04, runs all three carton packers. Each carton packer has a Flex I/O adapter with modules configured for remote I/O. Sensors located throughout each cartoner send inputs to the Flex I/O modules regarding the status of cartons being handled. Upon receiving input from the Flex I/O modules, the PLC responds, according to its ladder logic program, with outputs triggering specific actions to occur. In this way, all three cartoners are synchronized. Empty cartons index, robotic heads pick and place, filled cartons discharge, and so forth—all of it timed to perfection.
This networked approach, as opposed to the more traditional hard-wiring, is a sign that Planters is keeping current with the latest in line-controls technology. A single, two-wire cable linking all three cartoners and their common PLC takes the place of hundreds of wires that would have been needed if the system were hard-wired. In addition to making the installation simpler, faster and less costly, the Flex I/O system makes for easier maintenance and repairs, says Planters electronics technician John Slankard. “If an input or output on a module shorts out, you just remove that module and plug in a new one,” says Slankard. “You don’t have to unwire a bunch of wires, you just plug and play.”
Complementing the Flex I/O package are six servo motor/servo amplifier pairs, supplied by Rexroth Indramat (Hoffman Estates, IL), on each six-axis cartoner. The motors are “smart” enough to understand signals sent by the PLC and then execute the pick-and-place motions according to instructions. They also simplify changeover. An operator uses the Allen-Bradley PanelView 550 human/machine interface panel to select the desired product from a menu on the screen and, voila, programming directs all robotic loading head movements to automatically change.
The PanelView is also an important tool for diagnostics, as any fault on the cartoners will be displayed on the screen. Potentially it could be any one of a hundred or so possible faults. This way, by a simple glance at the screen, operators know exactly where the fault is.
See the main story that goes with this sidebar: Planters picks a packing line
