IPC Subgroup
H04M 3/62 Keyboard equipment
Introduced: September 1968
Last revised: January 2006
Full Title
Automatic or semi-automatic exchanges > Semi-automatic systems, i.e. systems in which the numerical selection of the outgoing line is under the control of an operator > Keyboard equipment
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC COMMUNICATION TECHNIQUE
- Subclass:
- TELEPHONIC COMMUNICATION