An attempt has been made to execute a robot-control command or instruction in one of the following invalid situations: (1) The system is not configured to control a robot. (2) There is no robot connected to the system. (3) The robot is attached to a different program task. (1) Make sure the system is booted from the proper system disk or remove the robot-control instruction. (2) Connect the robot or enable the DRY.RUN system switch. (3) Modify the program logic as required to ensure that only one program task is controlling the robot at any given time.