PURPOSE: To enhance an operation control processing efficiency by providing a display block equipped with display characters or a display board indicating operation conditions for the side surfaces of a regular polygon prism or a regular polygon pyramid capable of being engaged/disengaged.

CONSTITUTION: A rotary type operation display board 20 as an operating condition input means in an operation control system is made up of a display block A where a human suspension factor such as 'for switching over' and the like is displayed in the respective side surfaces of a regular polygon prism capable of being engaged/disengaged, and of a receiving base B provided with a display window, and the aforesaid display board is provided with switches corresponding to respective displays. When display characters indicating an operating condition are displayed over the display window, a switch corresponding to the display is turned on. Therefore, it is not required to depress the switch, the reliability of an operation control data is thereby enhanced. Besides, a signal concerning the aforesaid display is detected by a control unit 30, it is then forwarded to a host personal computer 50, and an operating condition display application and a summerizing application are multiply processed, so that an operation control processing efficiency can thereby be enhanced.