Recently, the scale of a works has become larger in every industries and information flow in the works has been more complicated.For example, an iron and steel works consists of blast furnaces, basic oxygen furnaces and rolling mills, where computers are installed for various controls. The raw materials and the products of each process must be weighed and analized, then the data must be sent to the computer immediately.In other words, it is necessary that measured data at random time series are transmitted on line from a data source point to a computer. So far, one to one direct wiring system has been adopted, but applying this manner to the whole works will result in such disadvantages that the total wiring length extends to several tens of kilometers, the interface device at each station becomes more complicated and expensive, and further, the new station requires new cables.Several conventional systems, time-division or frequency division, and centralized or looped, were compared and we decided to apply a new system.This paper describes the data transmission system so called “Data Highway System”, which is designed specially in order to improve the former disadvantages and becomes much more economical, flexible and reliable.This system has, at first, an ability to transmit the data between two stations directly without a special central processor such as a computer for data multiplexing. Sending stations and receiving stations are connected in loop by coaxial cables. The signals consist of receiver address, sender address and data, and are sent on the transmission line. Each station can decode address part and catch its own signal from the signal train on the loop.Secondly, the data from many stations are sent simultaneously in time-division manner, consequently, one signal transmission line is sufficient to the traffic capacity. From these points, this system has much more economical advantages, for example, the wiring length is reduced to under one-tenth.Thirdly, this system has higher reliability on account of several unique methods of checking and monitoring.This system is applied to the data communication among iron and steelmaking processes at the Fukuyama Works of Nippon Kokan.
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