Which statement correctly pairs the term with its state characteristic?

• A. Discrete devices have two states; Analog devices have infinite states
• B. Discrete devices have infinite states
• C. Analog devices have two states
• D. Both have two states only

Answer: (A)

Digital (discrete) devices operate in binary, with two distinct states: on and off (true or false). Analog devices, on the other hand, provide a continuous range of values within their measurement span, effectively infinite states. In PLC contexts, digital I/O handles switches and relays, while analog I/O reads sensors that vary smoothly over a range (like 0–10 V or 4–20 mA). This is why pairing discrete with two states and analog with infinite states is the correct description. The other statements misstate the nature of digital or analog states, or imply both have only two states.