RS-449
Encyclopedia
The RS-449 specification, also known as EIA-449 or TIA-449, defines the functional and mechanical characteristics of the interface between data terminal equipment and data communications equipment.
The electrical signaling standards intended for use with RS-449 are RS-422
for balanced signals, and RS-423
for the unbalanced signals, with data rates to 2 Mbit/s. The standard specifies DC-37
and DE-9
for the primary and secondary data circuits. Though never applied on personal computer
s, this interface is found on some network communication equipment. The full title of the standard is EIA-449 General Purpose 37-Position and 9-Position Interface for Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange.
EIA-449-1 was rescinded in January, 1986. Superseded by EIA/TIA-530-A
, the final version EIA-449-1 was withdrawn in September, 2002.
The electrical signaling standards intended for use with RS-449 are RS-422
EIA-422
RS-422 is a technical standard that specifies electrical characteristics of a digital signalling circuit. Differential-mode signals can be sent at rates as high as 10 million bits per second, or may be sent on cables as long as 1200 metres. Some systems directly interconnect using RS 422 signals,...
for balanced signals, and RS-423
RS-423
RS/EIA/TIA-423 is a standard for serial communications. It defines an unbalanced interface , with a single, unidirectional sending driver, and allows for up to 10 receivers . It is normally implemented in integrated circuit technology and can also be employed for the interchange of serial binary...
for the unbalanced signals, with data rates to 2 Mbit/s. The standard specifies DC-37
D-subminiature
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smaller connectors used on computer systems....
and DE-9
D-subminiature
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smaller connectors used on computer systems....
for the primary and secondary data circuits. Though never applied on personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
s, this interface is found on some network communication equipment. The full title of the standard is EIA-449 General Purpose 37-Position and 9-Position Interface for Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange.
EIA-449-1 was rescinded in January, 1986. Superseded by EIA/TIA-530-A
EIA-530
Currently known asTIA-530-A, but often called EIA-530, or RS-530, is a balanced serial interface standard that generally uses a 25-pin connector, originally created by the Telecommunications Industry Association....
, the final version EIA-449-1 was withdrawn in September, 2002.