(communications, standard)   An ITU-T recommendation on electrical characteristics for unbalanced double-current interchange circuits operating at data signalling rates nominally up to 100 kbps. This recommendation is also included but not published in ITU-T X series under alias number X.26. The circuit defined in this standard is used in other serial line standards such as EIA-232 and EIA-423, that implement single ended communication.

Last updated: 2002-10-05