DIFF Subgroup
H04M 1/53 Generation of additional signals, e.g. additional pulses
Introduced: July 1974
Full Title
Full titles differ between systems:
IPC:
Substation equipment, e.g. for use by subscribers > Devices for calling a subscriber > Generation of additional signals, e.g. additional pulses
CPC:
Substation equipment, e.g. for use by subscribers (subscriber services or facilities provided at exchanges H04M3/00; prepayment telephone coin boxes H04M17/00; current supply arrangements H04M19/08) > Devices for calling a subscriber (H04M1/66 takes precedence) > Generation of additional signals, e.g. additional pulses
IPC and CPC are identically structured here. All 1 subcodes exist in both systems.
Child Classifications
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- H04M 1/54 Arrangements wherein a dial or the like generates identifying signals, e.g. in party-line systems IPC+CPC Available in IPC and CPC