IEC 61850-7-4 Communication networks and systems for power utility automation - Part 7-4: Basic communication structure - Compatible logical node classes and data classes*, 2020-01-01 Update
IEC 61850-9-2 Amendment 1 - Communication networks and systems for power utility automation - Part 9-2: Specific communication service mapping (SCSM) - Sampled values over ISO/IEC 8802-3*, 2020-01-01 Update
BS EN 60255-127:2014 history
2014BS EN 60255-127:2014 Measuring relays and protection equipment. Functional requirements for over/under voltage protection
1998BS EN 60255-3:1998 Electrical relays - Single input energizing quantity measuring relays with dependent or independent time