Development, Medical Gas Pressure Distribution Monitoring System Based On Modbus Protocol

Based on an actual project, this paper proposes the software and hardware design and realization method of the medical gas pressure distributed monitoring system. The system is based on the modbus communication protocol.At first, we determine the basic functions which the system due to achieve by analyzing the whole system requirements, complete the selection of pressure transmitter referring to GB50333-2002. Then according to the basic functions of the system which is expected to reach, we complete the hardware circuit design and software programming of slave computer in different modules. And then we complete the man-machine interface design and programming of host computer in visual studio 2005 platform. Finally, the software and hardware debugging of the whole distributed monitoring system is done, proving that the system is reasonable and feasible.The physical layer, data link layer and application layer of modbus protocol is introduced in this paper in detail. According to the actual needs of our subject, a reasonable expansion and optimization on the application layer of modbus protocol is made. Because of this, modbus packets can accommodate more useful information, which improving the efficiency of communication. In the design process of the software interface, the ergonomics is considered as a guideline. Thinking of user' cognitive level, habit, comfort and other aspects, the interface must be reasonable, efficient and friendly. This system has been used in several hospitals since its construction. It proves that the system is stable and reliable. The system achieves good results resulting in a certain economic benefit.