The cold light lamp regulator is controlled by the PLC digital output module to automatically adjust the illumination time (12 h/12 h or 10 h/14 h light/dark cycle) according to animal behavior. The illumination time and intensity (5-10, 15-20, and 100-200 lx) can be set from the touch screen by the operator and automatically executed. The lamps also can be switched on or off manually to meet different lighting requirements during an experimental procedure.