Which statement correctly describes fixed-automation devices?

Fixed-automation devices are characterized by their use of mechanical means, such as cams and gears, to perform specific, repetitive tasks. This type of automation is designed for high-volume production where the tasks are predictable and consistent. The mechanical components allow these devices to efficiently handle tasks that don't require flexibility or frequent changeovers.

This fixed structure makes them ideal for mass production, where the same operation is performed continuously. Because of the robust nature of their design, these devices excel in environments where production runs are long and where setup times for new tasks or products would be too costly and time-consuming.

The other statements do not accurately capture the essence of fixed automation; they either reference variable tasks, software control, or suitability for small-scale production, which are characteristics more aligned with alternative forms of automation such as flexible automation or programmable automation.