Which technique involves checking the value of each instrument sequentially?

Which technique involves checking the value of each instrument sequentially?

• A. Tone-frequency multiplexing
• B. Scanning
• C. Polling
• D. Multiplexing

Answer: (B)

Scanning describes the process of cycling through each instrument in a fixed order and reading its value in turn. This creates a continuous loop that checks all inputs one by one, making sure no instrument is overlooked. It’s commonly used in data acquisition and control systems to monitor many sensors with a single readout path. Polling also involves checking devices, but scanning emphasizes a automatic, cyclic sequence through all channels, whereas polling centers on a master actively requesting data from each instrument. Tone-frequency multiplexing and multiplexing in general refer to sharing a channel among multiple signals, not to the technique of sequentially reading each instrument.

Scanning describes the process of cycling through each instrument in a fixed order and reading its value in turn. This creates a continuous loop that checks all inputs one by one, making sure no instrument is overlooked. It’s commonly used in data acquisition and control systems to monitor many sensors with a single readout path.

Polling also involves checking devices, but scanning emphasizes a automatic, cyclic sequence through all channels, whereas polling centers on a master actively requesting data from each instrument. Tone-frequency multiplexing and multiplexing in general refer to sharing a channel among multiple signals, not to the technique of sequentially reading each instrument.