keyboard interface
3.The actualization of intercommunion between machine and people of DSO designed in this paper adopt keyboard interface, keyboard adopt 5×7 matrix layout, keyboard scancode is adopted by row and arrange scanning, scan working adopt circle inquire, serial port finish connecting keyboard to main computer.
7.The monitor system is made by the 16-bit fixed-point DSP TMS320LF2407A , the precise potential transformers and current transformers, anti-alias filter, 6-channel simultaneous sampling analog-to-digital converter ADS7864, keyboard, graphics LCD , RS-232 interface etc, which is cheap in cost and easy to control.

