What is analog data?

• A. A continuous range of values representing a measurement.
• B. Discrete ON/OFF electrical signals.
• C. A digital encoding of data.
• D. A sequence of fixed binary numbers.

Answer: (A)

Analog data means signals that can vary continuously, representing a physical quantity with essentially unlimited granularity within a range. This lets a measurement change smoothly from one value to the next, rather than in fixed steps. Digital data, by contrast, uses discrete levels—ON/OFF or binary states—so it changes in steps. In an industrial setup like a 4-20 mA loop, the measured process value is carried as an analog current that can vary fluidly from 4 mA to 20 mA to reflect the true value. Digital encoding or fixed binary sequences are used for digital communications and control signals, not for representing the continuous measurement itself in these loops. So describing analog data as a continuous range of values is the correct idea.