IEC 62026-7:2010 specifies an interface system providing bit-level and word-level communication between a controller and control circuit devices such as sensors, actuators, and switching elements. The interface system uses cabling with round or flat profiles containing a two conductor signalling pair and optionally a two conductor power supply pair. This part establishes requirements for the interchangeability of components with such interfaces. This standard cancels and replaces IEC/PAS 62026-7 published in 2009. This first edition constitutes a general technical revision with clarifications only and with no significant change in the technology.