JPH0228190B

PURPOSE:To prevent a malfunction by detecting a transformation of a parameter, by providing a check value use RAM means for calculating and storing a check code of a parameter part, when a power source for setting the parameter is off. CONSTITUTION:A program supplied from a host machine HM is stored in a program use RAM means B, and a parameter for generating plural kinds of work use programs is stored in a parameter use RAM means D. When a power source for setting a parameter is off, a check code of a parameter part is calculated, and its value is stored in a check value use RAM means F. When the power source is on, an error check is executed by a check value prior to an execution of the work use program. In this way, even in case when the parameter has been transformed due to the cause of a malfunction, etc., a malfunction of an apparatus can be prevented.