Design And Implementation Of Switch System To Standard I/O Devices Of Operating And Expressing Machines

As the man machine interface in the computerized interlocking-control system (CIS), the operating and expressing (O&E) machines play a key role in receiving command and devices' states. To improve reliability, the dual-hot-backup mode is used by the (O&E) machines, which use only one set of standard I/O devices (mouse, keyboard, monitor, audio device etc.). I/O devices' access switch between the dual O&E machines is realized by the switch system, which reduces the fixture and facilitates the operation. The dual-hot-backup mode is used by the switch system too, and the reliability of O&E lay and CIS is improved.Related technology devices in China are in the initial application stage, and they are similar in system design, but different in implementation, which need to be unified. All devices have problems of I/O device miss and signal interference, which may affect the operation and the system reliability & availability. A set of hot-backup structure switch system was designed based on the application background of the JT-DE CIS and the switch system functional requirement analysis. System's hardware and software were developed.The main works of this paper are as following:Firstly, the system research background and application status was introduced; the system external and its own functional requirements were analyzed; the system scheme was designed; the system hierarchy was delaminated; the logic of system design process was interpreted, and the system functional decomposition was proposed.Secondly, the system hardware architecture was designed based on the cabinet structure of CIS; the main-control PCB for control, communication & state acquisition was developed based on the hardware functional analysis of organizing & coordinating lay; the mouse switch PCB for mouse and keyboard message switch, the audio switch PCB for audio switch, and the video switch circuit board for video switch were developed based on the functional analysis of implementation lay units.Thirdly, the main-control PCB software for ruling, fault diagnosis, communication, synchronization, control & state acquisition was developed based on the software functional requirement analysis of organizing & coordinating lay, and the mouse switch PCB software for mouse keyboard simulation & message transmitting were developed based on the software functional requirement analysis of mouse switch PCB. Fourthly, based on the application background of the JT-DE CIS, the switch system debugging in the laboratory and the locale were completed through analysis of system debugging principle, method, condition, process & result, and the system performance was validated.