A Programmable Logic Controller [PLC] is a self contained microprocessor controlled interface designed to control or monitor some other I/O function. A less common term for Programmable Logic Controller is PLCs. Related topic Field Buses.
Delta Electronics, Inc. {PLC Manufacturer}
Entertron Industries, Inc {Card and Module based PLCs}
Foxboro {Distributed Control System (DCS)}
GE Fanuc {Modular Programmable Logic Controllers}
Hitachi {Programmable Logic Controllers}
Keyence {Programmable Logic Controller with a built-in data window}
Panasonic {PLCs}
A Programmable Logic Controller is not an integrated circuit but a component or piece of equipment. A box or case with an embedded controller and I/O to control external devices.