Patent ID: 7086518

Claim:
A method of supplying workpieces to a plurality of workstations, each of said workstations being operable to generate and transmit a call signal, a ready signal, and an error signal, said method comprising the steps of: (a.) receiving all call, ready and error signals transmitted from the workstations; (b.) for all received call signals, determining a selected one of the call signals, which is the oldest one of the call signals that has not been responded to and has not come from a workstation that has also transmitted an error signal; (c.) responding to the selected one of the call signals by moving a selected one of the workpieces from an input area to a selected one of the workstations, which is the workstation that transmitted the selected one of the call signals; (d.) determining if a ready signal or an error signal has been received from the selected one of the workstations; (e.) if an error signal has been received from the selected one of the workstations, returning directly to step (b.); (f.) if neither a ready signal, nor an error signal has been received from the selected one of the workstations, returning to step (d.); and (g.) if a ready signal has been received from the selected one of the workstations, loading the selected one of the workpieces into the selected one of the workstations; and (h.) returning to step (b.).