Remote test circuit for channel terminal

Claim 1

A communication system comprising: a data center having a master data terminal and a data channel end connected to said master data terminal; a multi-junction unit for distributing data from said data center to a plurality of channels and feeding data form said plurality of channels to said data center; and multiple channel terminals each being connected to a respective one of said channels and including a slave data channel end which is connected to said multi-junction unit and is provided with an apparatus for setting up a return path between said channel terminal and said data center, and a slave data terminal for interchanging data with said slave data channel; wherein said apparatus for setting up a return path comprises: test start signal detecting means for detecting a start signal sent from said data center to produce a test start detection signal; an address signal detecting means for detecting an address which is identical with an address from address signals sent from said data center and producing an address detection signal; and control means for supplying an idle code to said slave data terminal in response to the test start detection signal and for connecting an output of said multi-junction unit to said slave terminal in response to the address detection signal.