With the Sterling Systems & Controls bulk bag unloading and weighing system, an operator hangs a full bulk bag in place within the upper part of the support structure and routes the bag spout through the iris valve and into the bag clamp. The operator then opens the bag spout to start the flow of the material into the bulk bag unloader, turns on the main power to the variable frequency drive and control panels, and disengages the emergency stop. With the control set for auto, the operator sets the target weight, fast cutoff and slow cutoff set points, as well as the slow fill speed. Pressing the start batch pushbutton begins the automated process of bulk bag discharge, material weighing and dispensing.