TABLE OF CONTENTS The Recommended Standard system (RS-232) was elaborated in 1962 at the request of the American Electronic Industries Association, in order to standardize the signal parameters and the construction of devices capable of exchanging digital data through a telephone network. In the RS-232 interface system, a mode of establishing and realizing communication between two terminals was defined; the terminals were named Data Terminal Equipment (DTE). Each of two DTE items is connected to a telephone line through a modem, marked with a Data Communication Equipment (DCE) symbol. This interface system was internationally recognized, and, after slight changes made in 1969, it was given the RS-232C name and the status of a U.S. standard. The RS-232C system is currently the standard of serial interface, applied to exchange digital data (information) between DTE devices, also without modems. It is more important that the RS-232C interface has become the standard for series line to connect a personal computer to peripheral devices (e.g., to a mouse or a modem); only then has it become widely known to myriads of computer users. The RS-232C system is a basis for international standards V.24 (functions, lines, cabling, connectors) and V.28 (electrical parameters of circuits defined in V.24) accepted for serial interface system by the International Consulting Committee for Telephony and Telegraphy (CCITT). The parameters of the RS-232C interface system were also standardized by national standardization institutions in many countries.
A block diagram for a digital system exchanging data between DTE...
