Perpustakaan Digital ITB

The dynamic data transmission technology of an expendable current profiler is proposed in this paper. Two parallel varnished wires are employed as the data transmission medium. By testing the transmission properties of the varnished wires, a baseband transmission system is studied and designed. An optocoupler is used as the physical layer for data transmission. The data transmission protocol is modified and optimized in accordance with the RS232 protocol, and the Manchester code is superimposed. According to the results of indoor and marine tests, the data transmission distance of the designed system, which employed a 0.1-mm-diameter varnished wire, extends to 2 km with high accuracy for data transmission, exhibiting excellent performance. Moreover, this data transmission technology could be used for other expendable marine-environment parametric measuring instruments such as an expendable bathythermograph and expendable conductivity temperature depth profiler.