METHOD OF REPRODUCING STATUS OF MONITORING SCREEN

PURPOSE:To eliminate the need for the printing with a printer at every input of a monitoring data by retrieving the logical state change of a monitoring data stored in a filing device at the optional time while using a decided time as a retrieval item and displaying the result on the screen of a display device. CONSTITUTION:When the past state of a monitoring data is reproduced, a retrieval request and a retrieval item to a retrieval processing section 6 are inputted from a keyboard 15. As for the retrieval item, the time when the status to be reproduced takes place and which logical state change exists is decided is used as the retrieval key and the result is stored in the filing device 7 together with the status of the monitoring data. Then a retrieval processing section 6 is started by the retrieval request and the data is retrieval from the filing device based on the retrieval item. The retrieval data is expanded into the same format as the present status display via a pattern display processing section 3, displayed on a display device 4 and observed. Thus, the printing of the monitoring data at every input with a printer is not required.