In this paper we investigate dynamics of a system of planar piecewise isometric systems. At first we introduce a coding map on a system of planar piecewise isometric systems then we extend the coding map onto the entire phase space and prove that there exist an essential coding for a singular point. At the end of this paper we investigate some important sets including singular sets, exceptional sets, rational sets, etc... generated by a system of planar piecewise isometric systems.