4

 

RS-232 is an interface that is suitable for many basic communication tasks

between two computers. This chapter introduces RS-232 signals and interfac-

ing options.

    !

RS-232 is designed to handle communications between two devices with a dis-

tance limit of around 80 to 130 ft, depending on the bit rate and cable type.

RS-232 uses unbalanced, or single-ended, lines. Each signal in the interface has

one dedicated line whose voltage is referenced to a common ground.



In popular use, RS-232 refers to a serial interface that complies with much of

the standard TIA-232-F: Interface between Data Terminal Equipment. The name

RS-232 dates to an earlier edition of the standard.

The standard’s current publisher is the Telecommunications Industry Associa-

tion (TIA). Previous versions were a product of the Electronics Industries Asso-

ciation (EIA). A similar standard is encompassed by V.24 and V.28 from the