Abstract: In a writing device, a controller controls an authentication communication unit so as to transmit authentication data to a display device, prior to writing main data into the display device, in order to specify the display device into which the main data is to be written. After carrying out the authentication, the controller controls a main communication unit so as to transmit the main data stored in a memory to the display device into which the main data is to be written, by wireless communication. In the display device, a controller controls an authentication communication unit so as to receive the authentication data from the writing device. The controller controls a main communication unit so as to receive the main data from the writing device by wireless communication after the completion of the authentication. Therefore, when the main data is written into the display device from the writing device, it is possible to avoid wiring problems, and provide the display device with an improved appearance.

Abstract: A system for designing visual information on a monitor unit which enables the use of the monitor unit manufactured at a reduced cost but assures rapid reproduction of the intended visual information. The monitor unit is utilized in combination with a programmable logic controller (PLC) for monitoring a task to be performed by I/O devices managed by the PLC. The monitor unit includes a display, a controller section, and a memory. The system includes an image design tool operating on a personal computer for creating a source display code of the visual information to be reproduced on the display. The image design tool has a conversion means which translates the source display code into a corresponding bitmapped image and exports the bitmapped image to the monitor unit for immediate reproduction of the visual information on the display.