EN 50042:1980

This standard applies to switching devices which are able to operate only when completed with external associated electronic circuit components and contacts. The rules in this standard apply only to terminals for external associated electronic circuit components and contacts. These are a supplement to the general rules for the marking: of control supply terminals (see EN 50 005 clause 3.1), and of terminals for internal auxiliary contact elements (see EN 50 005, clause 4.2). The use of this standard is recommended where terminal marking is a requirement of the relevant standard for switching devices or is usual practice