PURPOSE: To make it possible to modify control conditions of a processor without causing a device to malfunction, by rewriting set information into a primary setting area from a temporary setting area from a keyboard.

CONSTITUTION: To modify control conditions of one group 1 previously set, pushing buttons RECALL, "1" and ENTRY on keyboard KB writes the contents of primary setting area m1 into temporary setting area m0 and the contents are displayed on cathode-ray tube display device CRT. Thenk required information setting modification is performed successively, and consequently while only the contents of temporary setting area m0 are modified, the contents after the modification and "NOTSTORE" are displayed on display device CRT. With buttons FUNCTION and ENTRY on keyboard KB, the contents of temporary setting area m0 are written into primary setting area m1 for group 1 and "STORED" is displayed on display device CRT. In addition, the timing of rewriting is automatically controlled, so that the control operation of processor CPU is not distrubed.