Glossary · Automation fundamentals, platforms and components
Microcontroller (MCU)
Also known as: MCU, Microcontroller unit
German: Mikrocontroller
In embedded electronics, a microcontroller (MCU) is a single integrated circuit that combines a processor core, program and data memory and peripherals such as timers, analog-to-digital converters and serial interfaces, and runs the firmware that controls a device.
- Automation components
In one sentence
A microcontroller is a single chip with processor, memory and peripherals such as timers and serial interfaces that runs a device's firmware.
Example
In a motorized valve actuator, a microcontroller reads the position sensor, talks to the motion control IC over SPI and reports the valve state over a fieldbus.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
How it applies
- Engineering: In drive electronics the MCU runs the application logic and communication, while time-critical current control often runs in a Motion control IC. The split decides where parameters live and who reacts to faults.
- Commissioning: Firmware is flashed via a debug interface or a bootloader; the version must match the hardware revision and the documentation.
- Operation: Watchdogs restart the MCU after a hang; the device state after such a restart must be defined.
- Documentation: Identify the firmware version and how to read it out, and describe the update procedure. In system descriptions, show which functions run on the MCU and which in other ICs, so readers know where a setting takes effect.
Microcontroller vs. PLC
A microcontroller is a component on a circuit board, programmed in C or similar languages by the device manufacturer. A Programmable logic controller (PLC) is a complete industrial controller programmed by the machine builder in IEC 61131-3 languages; inside, it contains processors of its own.