IEC 60870-1-2:1989

Telecontrol equipment and systems. Part 1: General considerations. Section Two: Guide for specifications

IEC 60870-3:1989

Telecontrol equipment and systems. Part 3: Interfaces (electrical characteristics)

IEC TR 60870-1-1:1988

Telecontrol equipment and systems. Part 1: General considerations. Section One: General principles