ERROR HISTORY RECORDER

PURPOSE:To display an error history on a display means by constituting the title recorder so that when an error is generated, an error history generating means stores the present data and time from a time counting means having a calendar function, and also, stores the error cause and an error code as error information. CONSTITUTION:When a control part 3 for executing a prescribed operation and a control of a machine tool 5 recognizes a fact that an error is generated, based on working information and state information of a mechanical input part 6, a processing which is being executed at present is shifted to an error processing routine, and the error cause is specified. When the error cause is specified, the control part 3 stores the error cause and an error code corresponding to its error cause in an error display frame memory 7. A display device 8 displays the error cause and the error code which is stored in said memory 7. Also, the control part 3 brings an error pointer to increment, and stores the error code and the error cause together with a data of year, month, day, hour, minute, etc., from a timepiece with a calendar, in an area of an error history storage part 13.