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PCE
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DIFF Subgroup
H04Q 9/12

using combinations of frequencies

Introduced: September 1968

Full Title

Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom > Calling by using continuous AC > using combinations of frequencies

No child classifications to compare. This is a leaf node in both IPC and CPC.