EIA-422

ANSI / TIA / EIA -422-B (formerly RS-422 ) is the American standard, its international equivalent is ITU-T Recommendation V.11 (aka X.27 ). This technical standard provides balanced or differential unidirectional non-reversible data transmission over terminated or non-terminated lines, with point-to-point connectivity or for multi-drop message delivery.

Unlike RS-485 , which provides a multi-drop structure, EIA-422 / V.11 does not allow multiple senders, but allows multiple receivers.

The full title of the document governing this ANSI standard is “Electrical Specifications and Power Circuits for the TIA-422 Interface”. Published in May 1994, it is currently in revision B. Confirmed by the Telecommunications Industry Association in 2005.

The advantage of the standard is the data transfer rate of up to 10 mega baud for a 12-meter cable. Although the specification of the standard does not establish an upper limit, it shows a graph of signal attenuation with increasing cable length. The graph breaks off at 10 Mbps.