IEC 62026-1:2019 applies to interfaces between low-voltage switchgear, controlgear, and controllers (e.g. programmable controllers, personal computers, etc.). This document does not apply to higher level industrial communication networks that have become known as fieldbuses and are considered by IEC subcommittee 65C. This third edition cancels and replaces the second edition published in 2007. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition.