ABSTRACT:Industrialize along with the world to turn the progress with city quickly, the city will become the main place that the mankind live, coming to a decision the symbol that the city is mankind's civilization from here, the emergence that what to follow is a series of city transportation problem, and gradually serious, the traditional supervision mode has already can't satisfy the antinomy that the contemporary city transportation controls the system, requesting to a kind of more reasonable, the more simple city transportation control system appear, to guarantee that the safety of the city road is unimpeded.But control the system according to the PROFIBUS the spot city transportation of the total line exactly and thus a kind of system.This text describes a few transportation lights to control the characteristics of method first, then introduced the spot total line and its characteristicses that several types relatively spread, the point introduced the PROFIBUS characteristics and the development foregroundses, and elaborated the meaning of this topic and develop the trend;Carried on the design to the hardware immediately after, give the rushes toward the structure diagram, selecting the hardware parts need to combine detailed introduced its function, return to the transportation light hardware connects the line diagram and the hardware allocation tables;Then put forward according to the PROFIBUS the spot correspondence network project of the total line network and correspond by letter the principle, introduce the PROFIBUS agreement structure and saving agreement, detailed elaborated the structure, system behavior, data correspondence of and expand function etc.;Went into detail the system work method finally, and design the main procedure of a system, and input the output's protection.