Which statement accurately distinguishes analog and digital signals in mechatronics?

• A. Analog signals vary discretely; digital signals vary continuously.
• B. Digital signals are continuous; analog signals are discrete levels.
• C. In mechatronics, sensors often provide analog values that are digitized by ADCs.
• D. Both analog and digital signals are always continuous.

Answer: (C)

Signals in mechatronics are categorized by how they carry information: analog signals vary continuously in time and amplitude, while digital signals are represented by a finite set of discrete levels. This means digital signals are processed in steps rather than as a smooth curve, which is why digital systems use discrete values. In practice, sensors often produce analog values that must be converted to digital form by an analog-to-digital converter. The ADC samples the analog signal at a chosen rate and quantizes its amplitude into discrete levels, turning a continuous signal into a series of numbers that a microcontroller or digital processor can handle. The sampling rate and resolution of the ADC determine how accurately the original signal is represented and how much detail is preserved for subsequent processing. While some sensors output digital data directly, the common workflow in mechatronics is to use an ADC to bridge the analog world of sensors with the digital processing environment.