Mass Storage System Of Relay Protection On Vehicle Based On USB Host

In the field of aero refrigeration ,considering the problems such as bad resistant temperature,weak anti-electromagnetic interference,long maintenance time,low performance to price ratio in human-machine interface ( HMI) of air-condition unit for aircraft, as well as the high requirements of real- time data collection and data save, in this paper, mass storage system of relay protection is designed in the military environment. MCU(Microprogrammed Control Unit) MSP430 is used as the main controller of the system;LCD with T6963C controller integrated in is used as the display module. PPI protocol in RS485 is used as the communication to this system and Siemens S7-200. SL811HS is used as the USB controller, JTAG interface is added for system debug.Protel layout software is used.In this way,the system hardware is carried out.(1)Analysis several relay protection of air-condition unit for aircraft at home and abroad, comparing their advantage and disadvantage, and combine with the environmental requirements at airport, the design of relay protection mass storage is prompted.(2)The principle of relay protection mass storage based on USB Host is researched. And combined with the special requirements about wide temperature -40℃to 120℃and strong anti-electromagnetic interference, Designing the schematic. The reliability of the military environment is designed,and make them meet essential condition the system needed from software and hardware.(3)The software is designed, firstly the data is intercepted,which Siemens S7-200 sends to serial port of PC, and analogs Profibus standard, some key frame format of PPI protocol is reached ,facilitating the communication PLC to the system. and then, consider the requirements such as historical data showed, anti-control PLC and the data is transferred to USB when the data temporary deposit is full,the display module of system is designed optimizely. Finally,design the programabout these aspects: USB service established USB drive of bottom based on host-device, control transmission, Mass Storage class protocol and U disk file system and so on, achieving the USB Host storage.(4)Complete test on system and field.based on USB storage, anti-interference and the limited temperature, it enables them to meet the special requirements. The result shows that the system runs well, the functions are not affected under vary interference andextreme temperature environment, the basic system functions are not affected, the occasional disturbance. the function of relay protection comes true,and makes the time short to 60%,which technician maintemces equipments,reducing the pressure that mass expenses brings the airline company because of the increasing equipments.In this paper, the design offers much helps to the airline company about saving expenses and technician maintences air-condition unit for aircraft quickly.