Which option best describes a control device that handles only one call at a time, providing an uninterrupted trip for each call?

• A. Sequential Intercom
• B. Duplex intercom
• C. Multi-call pushbutton
• D. Single Automatic Pushbutton

Answer: (D)

Understanding how control devices manage elevator calls is key. A single automatic pushbutton is designed to handle only one call at a time. When you press it, the system assigns that single request and proceeds with the corresponding elevator trip without being diverted or delayed by other pending calls. This guarantees an uninterrupted ride for that specific request.

In contrast, a multi-call pushbutton allows multiple calls at once, which can lead to overlapping requests and a ride that isn’t guaranteed to stay uninterrupted. Intercom options (sequential or duplex) focus on communication between parties rather than dispatching a single elevator trip, so they don’t fit the described behavior.