What speed setting should be used to test the vigilance feature of the RCT?

The vigilance feature of the RCT (Remote Control Transmitter) is designed to ensure that the operator maintains continuous attention while operating the machinery. Using the coast speed setting is appropriate for this test because it allows the system to operate at a reduced speed, which can help the operator focus on monitoring the surroundings without feeling rushed.

With the coast setting, the operator can observe the equipment's behavior and responsiveness effectively, making it easier to identify if the vigilance feature is functioning properly. At slower speeds, there's a more manageable pace for the operator to keep track of the situation, which is essential for assessing the alertness and responsiveness of the vigilance function.

In contrast, heavy, slow, or fast settings may either increase the risk of accidents (in the case of heavy or fast) or might not effectively engage the operator’s attention as needed for a proper vigilance test (in the case of slow). The selection of coast facilitates an ideal scenario for this assessment.