CPC Subgroup
H04Q 1/30 Signalling arrangements; Manipulation of signalling currents (multiplex systems providing for calling or supervisory signals H04J1/14, H04J3/12)
Full Title
Details of selecting apparatus or arrangements > Electrical details > Signalling arrangements; Manipulation of signalling currents (multiplex systems providing for calling or supervisory signals H04J1/14, H04J3/12)
7 direct subcodes
Child Classifications
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- H04Q 1/32 using trains of DC pulses (H04Q1/39 takes precedence)
- H04Q 1/38 using combinations of direct currents of different amplitudes or polarities over line conductors or combination of line conductors
- H04Q 1/39 using coded pulse groups
- H04Q 1/40 whereby duration of pulse or interval between two pulses is variable
- H04Q 1/44 using alternate current (H04Q1/50 takes precedence)
- H04Q 1/48 Induced-current signalling arrangements
- H04Q 1/50 Conversion between different kinds of signals