Which device accepts an on or off signal?

• A. Digital output
• B. Pseudopoint
• C. Latching relay
• D. Incremental output

Answer: (A)

Binary signaling is what this is about: a device that operates in only two states, on or off. A digital output is built to take a control signal that is either high (on) or low (off) and then drive its output to match that state. In practice, when the control tells it to be on, the output provides power to a load; when told to be off, it stops providing power. Other options don’t fit this straightforward two-state role: a pseudopoint isn’t a standard control device, an incremental output sends pulses for position or event counting rather than a steady on/off condition, and a latching relay holds a state after a pulse but isn’t the simple two-state output device used to directly switch loads in response to a binary command.