PURPOSE: To automatically secure the coincidence between time points of a computer system by automatically obtaining the coincidence of time points among plural computers and therefore omitting such trouble jobs to set those time points independently of each other.

CONSTITUTION: When an operator sets the time data by a time data setting circuit 2 via a computer 1, the circuit 2 fetches the input time data and converts this data into a time data type of the computer 1. Then the circuit 2 sets the converted time data at a time data setting address of the computer 1 and delivers the input time data to a data way time setting circuit 5. The circuit 5 sends the received time data to a data way 4, and a time data fetching circuit 6 of a process controller 3 fetches the time data to the controller 3 from the data way 4. Thus the coincidence of time points is secured between the computer 1 and the controller 3 serving as a computer.