A pressure controllercalibrator has multiple modules. A set of test patterns may be scanned through the scan cells such that cells belonging to FRUs within a tile may be concealed while analyzing the response of scan cells in the tile contributed by a different FRU. In response to the finger touch points, a display panel is controlled to display the virtual keyboard, wherein shape and size of the virtual keyboard are determined according to at least coordinates and touch areas of the finger touch points. The system can communicate with personnel or devices to raise an alarm or cause corrective measures to occur.