Q: Is There Anything Better Than the PLC?
Almost every plant manager has wondered at one time or another: “Isn’t there a better way to manage my operations? Is there anything out there that works better than a PLC (programmable logic controller)?”
A: Almost—But Not Quite.
The answer is: not quite yet, said Jim Wright, the Electrical Product Manager at IBT Industrial Solutions. However, newer, “smarter” technology is making industrial control devices better—and easier—to operate than ever.
“For many years, the PLC has been the backbone of industrial control devices,” Wright said, adding that the PLC automates processes, turns machines off and on, collects data, and shares that data with other devices. “The challenge is that it’s a ‘black box’ that can be problematic. A lot of things can go wrong with it.”
More: Need Siemens? IBT Has It
Issues with the PLC
Wright said that PLC’s have a number of traditional issues. The long runs of wire can easily get cut or come loose. Also, induced magnetic fields can create false signals that are wrongly interrupted by the PLC.
“The idea is that our machines could run better if the logic is decentralized and information is shared from device to device across a shielded network, rather than across wires,” Wright said. “This concept is not new, but today’s technology has finally advanced to the point where it can be industrially hardened to use in a harsh environment.”
Better Technology: “Smart” Devices
The solution? Devices that allow a machine to run faster and more accurately—with less waste and downtime. Smaller, smarter devices without wires would also free up panel space and expensive plant floor “real estate” for other applications. For example, “smart devices” such as remote I/O devices can replace the huge bundle of wires previously required to operate the PLC—and send data across a single CAT6 cable.
Some devices now also have embedded Ethernet capability that can be accessed via an internet page. This allows plant managers to log in from home to monitor the status of individual motors and machines—or an entire operation.
Example: Simocode Pro V
One example of this newer, smarter technology is the Simocode Pro V from Siemens, used with a Profinet network. Simocode is a smart overload relay capable of monitoring motor performance and sharing that data across the Profinet network for diagnostic purposes, as well as for production monitoring.
A Simocode device is typically located between the motor starter and the motor. It is used not only for communication, but also for motor protection.
“Can the PLC be replaced? The answer is maybe,” Wright said. “At the very least, the new smart devices can communicate useful info across a network that is less susceptible to electrical noise, and can turn loads off and on, monitor work, and help predict when maintenance might be necessary.”