Abstract: A solid state control panel system utilizing optical coupling between a graphic control panel and a hand-held probe is disclosed. Separate light emitting control diodes and display diodes are utilized on the graphic panel. In response to a coded optical coupling between selected light emitting diodes on the panel and a light sensitive diode in the probe, various switching functions are performed. The system provides three different types of coding for each complete switching operation, namely, time coding, polarity, and pulse sequence coding. The probe includes means to inform the operator when proper optical coupling occurs; and is so constructed mechanically that it can be operated by pressure engagement with the panel, or as a gun. The system is structured to provide various types of switching functions, including the provision for selecting any one of a plurality of individual switches in its present state for display and control with each selected switch having a multiplicity of states.