Physical layer (OSI)
Open systems interconnection
Optical fibres
Electrical properties and phenomena
Digital signals
Design
Coaxial cables
Communication networks
Data transmission
Clocks
Interfaces (data processing)
Information exchange
Electronic equipment and components
Data transfer
Transformers
Industrial
Accuracy
Fibre optic connectors
Electric connectors
Topology
Coding (data conversion)
Process control
Receivers
Control systems
Transmitters
Transceivers
Electric cables
Circuits