RS-423

Domain	Definition
Computing	RS-423 A common electrical specification for the signals on a serial line. When no data is being transmitted, the serial line is at a logical zero (+3 to +15 Volts). A logical one is represented as a signal level of -15 to -3 Volts. In practise, one often finds signals which switch between nominally +4.5 and +0.5 Volts. Such signals are large by modern standards, and because the impedance of the circuits is relatively high, the allowable bit rate is modest. The data is preceded by a start bit which is always a logical one. There may be seven or eight bits of data, possibly followed by an even or odd parity bit and one or two stop bits. A "break" condition is a continuous logical one on the line which is what would be observed if nothing was connected. EIA-232 specifies the physical connector normally used for RS-423 lines. (1995-02-02). Source: The Free On-line Dictionary of Computing.
Source: compiled by the editor from various references; see credits.