Direct digital control (DDC) is best described as?

• A. A control where controlled and monitored analog or binary data are converted to digital format for manipulation and calculations by a digital computer or microprocessor, then converted back to analog or binary form to control physical devices.
• B. A purely analog control system.
• C. A manual control method with local switches.
• D. A wireless control system that doesn't use digital processing.

Answer: (A)

Direct digital control relies on converting sensor data into digital form, processing it with a digital computer or microprocessor, and then converting the results back to analog or binary signals to drive physical devices. This digital processing enables programmable, precise, real-time control and easy integration with building management systems. The other descriptions don’t fit: purely analog control lacks digital processing, manual control depends on human input, and a wireless system that doesn’t use digital processing isn’t performing direct digital control.