Patent ID: 7277785

Claim:
A method of calibrating a PTO for driving a header of an agricultural windrower, comprising steps of: proving a window including a PTO having a signal controlled device for controlling pressurized fluid flow through the PTO to a header for controlling a speed of operation of the header; providing a programmable control module operable for controlling a speed of an engine of the windrower, the programmable control module being connected with the signal controlled device and operable for outputting control signals thereto having variable signal values, and; wherein the control module is program as part of a calibration routine for automatically: controlling the speed of the engine at a plurality of predetermined engine speeds, respectively; and while the speed of the engine is controlled at each of the predetermined engine speeds: outputting an initial control signal to the signal controlled device having a predetermined initial signal value within a predetermined signal range for the engine speed; determining an operating speed of the header resulting from the outputted initial control signal; comparing the operating speed of the header resulting from the outputted initial control signal to a predetermined target speed value for the header, and: if the operating speed of the header resulting from the outputted initial control signal is equal to the target speed value, storing information representative of the initial signal value; and if the operating speed of the header resulting from the outputted initial control signal is not equal to the target speed value, then calculating and outputting at least one changed control signal to the signal controlled device having a signal value within the predetermined range and incrementally greater or less than the initial control signal value, for changing the operating speed of the header so as to equal the target speed value, and storing information representative of the signal value of the changed control signal for operating the header at the target speed.