Abstract: A conventional peripheral device of a programmable controller has a problem that the frequency of data communications between the PC and the peripheral device and between the peripheral device and a display increases and the updating rate of results of monitoring processes lowers so much as the number of programs for execution of monitoring processes increases. In view of the above, according to the invention, there are provided display means on which a plurality of windows are displayed; input means for specifying an arbitrary one of the plurality of windows; and managing means for outputting, to a programmable controller that is to display a processing result of a monitoring process to the specified window, monitoring request data for execution of the monitoring process, and for receiving a processing result of the monitoring process that is based on the monitoring request data.