Model a robot arm with 5 degrees of freedom and a gripper, along with two conveyor belts. The robot transfers a block from one conveyor belt to the other. One conveyor belt brings the block to the robot arm, and the other belt transports the block away from the robot arm. Variant subsystems permit the model user to configure the robot arm for different tests: 1. Full test with conveyor belts, load, and logic (default) 2. Box transfer test 3. Joint tests.