Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
H04M3/08—Indicating faults in circuits or apparatus
H04M3/12—Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04Q—SELECTING
H04Q5/00—Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange
H04Q5/02—Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange with direct connection for all subscribers, i.e. party-line systems