A method for the continuous storage of internal operating states and visualization of past sequences of operations, as well as to a robot and/or robot controller, wherein the robot is preferably mounted on or next to a processing machine, in particular an injection molding machine and serves for the removal, handling, manipulation or further processing of injection molded parts which have just been produced. The robot controller records data, in particular changes of state, positions, internal parameters, time stamps, etc., and in case of occurrence of an error this most recently recorded information is linked to the error and stored, whereby the changes of state until the occurrence of the respective error are simulated and visually displayed for an analysis on the basis of a virtual model of the physical robot.