Abstract: A method and apparatus for controlling the tools and machine is disclosed. A first selected location on the body of a fish conveyed in the direction of its longitudinal axis engages with a first feeler and effects an impulse counter to start to count pulses of a first frequency. A second selected location on the fish body then engages with another feeler and effects the impulse counter to count pulses of a second frequency and to add these pulses to the amount of pulses of the first frequency run up between the engagement of the first spot and the engagement of the second spot. If a designated total number of pulses, which is determined upon the distance between the place of engagement of the first feeler and the location of the tool to be controlled, have run up, the impulse counter is set to give a signal to a setting element controlling a tool or a guide so that the cutting of the fish is commenced at a precise desired point on the fish body.