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Publication date
Application filedfiledCritical
Publication of NL6613717ApublicationCriticalpatent/NL6613717A/xx
H04M3/22—Arrangements for supervision, monitoring or testing
H04M3/24—Arrangements for supervision, monitoring or testing with provision for checking the normal operation
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04M—TELEPHONIC COMMUNICATION
H04M3/00—Automatic or semi-automatic exchanges
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
H04Q1/00—Details of selecting apparatus or arrangements
H04Q1/18—Electrical details
H04Q1/20—Testing circuits or apparatus; Circuits or apparatus for detecting, indicating, or signalling faults or troubles
H04Q1/22—Automatic arrangements
H04Q1/24—Automatic arrangements for connection devices