The invention relates to a device for determining the position and direction of channel inlets and channel outlets in wastewater systems that, in the horizontal plane, lead into and out of sewer manholes. In this system, a file storage facility stores executable files that are called by a server in the host processor by way of an application programming interface. An inductive connector system may also be provided to allow transfer of data andor power between a data access point and a client system. The position designator 110 determines the displayed position of the child-frame video in accordance with displayable time information of the child-frame video and information on the displayed area or displayable area depending on time, included in the data for display. Upon release, the elastic material of the post causes the post to attempt to return to its original shape, thereby causing it to expand out and conform its shape to fit snugly against the user’s toes.