Data communication apparatus having improved transmission effici

Data communication apparatus with multi-address calling

Data communication apparatus with operation-stop function

Data communication network

Data communication network

Data communication network and method of communication

Data communication receiver having variable length message carry

Data communication system

Data communication system

Data communication system

Data communication system

Data communication system

Data communication system

Data communication system and data communication terminal applie

Data communication system and data communication terminal applie

Data communication system for activating remote loads

Data communication system with channel switches

Data communication system with key data bit denoting significanc

Data communication system with timed access to link

Data communication unit