A system and method are provided for use in establishing secure end-to-end communication links over a VPN gateway via a network interface unit. A first timing control circuit operates in synchronization with the operation of a drive circuit to control the operation of an analog processing circuit and an AD converter and writing of video data D1 into a line memory. The plurality of FGs are arranged in rows and columns with each of the FGs being configured to receive regular input signals, perform a logic operation, and generate regular output signals. Thus, a video signal in which a polarity is not inverted and no potential change occurs is supplied to the signal line later. The first chassis residing in a front compartment of the rack with a front side of the first chassis facing the front side of the rack. The process for an azo coupling reaction comprises carrying out a coupling reaction of a diazonium salt and a coupler to make the diazonium salt form color, and the coupler has certain specified structures.