A method for saving power in transmission of data across buses. One rollforming roller on each rollforming head is mounted on an eccentric so that a force supplied in the direction of material feed through the tooling rollers will increase the tooling gap therebetween. Second light sources are attached respectively to the left and right of a light guide member which is roughly W-shaped. During rotation of the head and shroud, air is drawn downwardly about the drive mechanism, through the channel inlets, into and through the channels and outwardly therefrom at a forward inclination about the line projecting from the housing thereby cooling the drive mechanism of the rotary trimmer and reducing aerodynamic drag on the line. The apparatus is capable of analyzing any portion of the packet including the header and payload. A determination is made whether a subset of the set of columns form a key for the right quantifier.