Production management system and method of transmitting data

A production management system for controlling a production line having a plurality of working stations having respective automatic machines controllable by at least one of sequencers and robot controllers, comprising:

• a plurality of pieces of production equipment, each of said pieces of production equipment including at least one of a sequencer and a robot controller, and an automatic machine controllable by said at least one of said sequencer and said robot controller;
• read-out means for reading type data applied to workpieces delivered to the production line;
• computer means having memories for storing type data and operation pattern data composed of bit trains, said computer means comprising a plurality of slave computers for controlling said at least one of sequencers and robot controllers, and a host computer for controlling said slave computers and supervising common information required by said slave computers, wherein said type data read by said read-out means are transmitted through said host computer to said slave computers, and said slave computers select operation pattern data corresponding to the transmitted type data;
• a main network by which said host computer and said plurality of slave computers are interconnected;
• a plurality of subnetworks by which said slave computers and said at least one of sequencers and robot controllers are interconnected;
• and
• the system being such that when a workpiece is delivered to the production line, the type data of the delivered workpiece are read by said read-out means and transmitted to said computer means, and said computer means transmits operation pattern data corresponding to the transmitted type data to said at least one of sequencers and robot controllers for controlling the automatic machine, and when said common information is to be modified due to a change in said pieces of production equipment, the common information stored in said host computer is modified into corrected common information, and the corrected common information is transmitted from said host computer to said plurality of slave computers, so that the common information stored in said slave computers can be modified by said corrected information.