Control became a system, which was first applied in the industrial field. In 1986, HONEWELL applied an outdated industrial control system software to buildings. Because industrial control pays attention to process control, and most of the control in buildings is environmental control, we have made corresponding research and development and improvement, and combined with some control units in buildings to form an independent building control system. This is the prototype of the earliest building control system. The software name of the first system is EBI.