Skip to content
PCE
Search Classifications
Search for IPC and CPC classification codes or keywords
CPC Subgroup
H04M 3/08

Indicating faults in circuits or apparatus

Full Title

Automatic or semi-automatic exchanges > Indicating faults in circuits or apparatus

4 direct subcodes

Child Classifications

Navigate with arrow keys, Enter to open

  • H04M 3/085
  • H04M 3/10 Providing fault- or trouble-signals
  • H04M 3/12 Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits
  • H04M 3/14 Signalling existence of persistent "off-hook" condition