What is a "system variable" in FANUC robots?

A system variable in FANUC robots refers to a type of variable that stores crucial information regarding the robot's configuration and operational parameters. These variables are integral to the robot's functioning as they provide real-time data and status about different aspects of the robotic system, such as position, speed, mode, and other essential attributes necessary for optimal operation.

System variables can change dynamically during the robot's operation and facilitate communication between the robot's controller and the user. They allow for greater flexibility in programming by enabling users to access and manipulate the robot’s operational state easily. This capability is vital for diagnosing issues, tuning performance, or adapting settings during different tasks.

In contrast, external communication variables specifically focus on interactions with other devices or software, while task duration variables serve distinct tracking purposes on how long tasks take to execute. User interface settings variables relate to the aspects of how users interact with the control interface, but do not encompass the broader operational and configurational data essential for robot performance. Therefore, the choice that defines system variables most accurately is indeed the one that emphasizes their role in storing information on configuration and operation.