Data transmission system of key telephone system
AssigneeTamura Electric Works, Ltd.
InventorsKenichi Kanno, Senji Okumura, Hisami Ojima
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Abstract
Disclosed is a system for transmitting data by a data pulse train obtained by a combination of "0" or "1" bit pulse signals through a pair of lines connected beween a main unit and a key telephone set. The system includes a counter for sampling the pulse train and counting "0" or "1" bit pulse signals; a comparator for comparing a count of the counter with a reference value; and a correcting section for adding "0" or "1" correction pulses so as to set the count to be the reference value when the count is different from the reference value.
Claims15
A system for transmitting data by a data pulse train, the data pulse train comprising a combination of data bit pulse signals each of which is characterized by either a first logic state or a second logic state, the data being transmitted through a pair of lines connected between a main unit and a key telephone set unit, comprising:
- for a unit transmitting data,
- counting means for sampling the data pulse train and counting data bit pulse signals of either said first or said second logic state;
- comparing means for comparing a count of said counting means with a reference value, said reference value being related to the number of bit pulse signals of said data pulse train and a correction pulse train;
- and
- correcting means for appending a plurality of correction bit pulse signals as said correction pulse train to said data pulse train such that the total number of bit pulse signals, of said data pulse train and of said correction pulse train, having said first logic state is made substantially equal to the total number of said bit pulse signals of said second logic state.
A system for the serial transmission of a data word from a transmission station to a receiving station, the data word being transmitted as a sequential train of data bit signals each of which has either a first or a second logic state, comprising:
- means for counting the number of transmitted data bit signals of said data word having one of said logic states;
- means, responsive to the operation of said counting means, for determining the logic states of data bit signals of a correction data word which, when appended to said data word, will cause the total number of data bit signals of each of said logic states of both said data word and said correction data word to be substantially equal one to another;
- and
- means, responsive to the operation of said determining means, for generating said correction data word and for transmitting said correction data word subsequent to the transmission of said data word.
Dependencies are inferred from the claim text.