1. A programmable display comprising: a display; a volatile memory; a nonvolatile memory configured to store control screen data received from a screen data creation device, the control screen data containing a plurality of pieces of screen data; and a controller configured to load the control screen data from the nonvolatile memory into the volatile memory at startup and selectively display a screen corresponding to any one of the plurality of pieces of screen data on the display on a basis of the control screen data loaded into the volatile memory, wherein the controller is further configured to determine whether the control screen data is for debugging based on information included in the control screen data; in response to determining, based on the information, that the control screen data received from the screen data creation device is not for debugging, the controller stores the received control screen data in the nonvolatile memory, and in response to determining, based on the information, that the control screen data received from the screen data creation device is for debugging, the controller loads the plurality of pieces of screen data contained in the received control screen data into the volatile memory and stores the received control screen data directly in the volatile memory.