When handshaking with other devices, what must a robot wait for before executing its routine?

In the context of industrial automation and robotics, handshaking is a communication process between devices to ensure that they are synchronized before executing any tasks. When a robot is handshaking with other devices, it often needs to confirm that it has received the necessary inputs to proceed safely and efficiently.

In this specific scenario, waiting for input from the Programmable Logic Controller (PLC) is crucial. The PLC acts as the central control system that manages multiple devices and processes within an industrial environment. By waiting for the PLC input, the robot ensures that it is aligned with the overall system commands and that it has the correct information to execute its routine correctly. This step is vital for maintaining safety and operational effectiveness in automated systems.

The other options, while relevant in different contexts, do not represent the most critical point of synchronization for the robot's operation. For instance, a signal from the sensor indicates some environmental condition but may not be the direct command for action. Similarly, output from the motor pertains to execution rather than the decision-making process, and a response from the actuator might be an effect of a command rather than the initial trigger needed to proceed. The input from the PLC is fundamental in coordinating actions among all linked systems in a consistent manner.