Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
192 words
A data communication unit sending a digital serial signal through a transmission route located in a communication network, said data communication unit including: a relay unit for generating a relay signal in response to a received signal; a transmitter for generating a transmission signal comprised of original data; and a sending controller coupled to said relay unit and said transmitter, said sending controller comprising: (i) a first timer which generates a trigger output TO after a non-signal state is continued for a first prescribed time TM, (ii) a second timer which starts a non-signal state and maintains said non-signal state for a second prescribed time TF after the end of sending said transmission signal, said sending controller further comprising, (iii) a sending control circuit which includes a selector means which selects a send signal among said received signal and said transmission signal by using said trigger output TO and determining whether a request-to-send signal RTS is active or inactive, and a non-signal generator means which maintains a polarity of said send signal as a fixed value for said prescribed time TF when said signal RTS becomes inactive during sending said transmission signal.
Claim 2
Dependent Claim
192 words
A data communication unit sending a digital serial signal through a transmission route located in a communication network, said data communication unit including: a relay unit for generating a relay signal in response to a received signal; a transmitter for generating a transmission signal comprised of original data; and a sending controller coupled to said relay unit and said transmitter, said sending controller comprising: (i) a first timer which generates a trigger output TO after a non-signal state is continued for a first prescribed time TM, (ii) a second timer which starts a non-signal state and maintains said non-signal state for a second prescribed time TF after the end of sending said transmission signal, said sending controller further comprising, (iii) a sending control circuit which includes a selector means which selects a send signal among said received signal and said transmission signal by using said trigger output TO and determining whether a request-to-send signal RTS is active or inactive, and a non-signal generator means which maintains a polarity of said send signal as a fixed value for said prescribed time TF when said signal RTS becomes inactive during sending said transmission signal.
Claim 3
Dependent Claim
25 words
A data communication unit according to claim 1, wherein said relay unit records information about the polarity of said signal RTS in said received signal.
Claim 4
Dependent Claim
68 words
A data communication unit according to claim 1, further comprising a transmission enable signal generator for generating a transmission enable signal TES when address information included in said received signal is coincident with the address of said data communication unit, said sending controller switching said send signal from said relay signal to said transmission signal only when said signal TES is output from said transmission enable signal generator.
Claim 5
Dependent Claim
31 words
A data communication unit according to claim 3, wherein said relay unit records information about the polarity of said signal RTS and information of its own address in said received signal.
Claim 6
Dependent Claim
58 words
A data communication unit according to claim 1, wherein said send signal has a signal format wherein the polarity reversal of said send signal occurs within a prescribed polarity-reversal period TP and it is configured such that the signal-sending state and the non-signal state is distinguished by whether or not reversal of polarity occurs within said period TP.
Claim 7
Dependent Claim
20 words
A data communication apparatus comprising a plurality of data communication units according to claim 5, located in a communication loop-network.
Claim 8
Dependent Claim
90 words
A data communication apparatus according to claim 6, comprising n (where n is an integer larger than 1) of said data communication units located in said communication loop-network having a second prescribed time TF i which satisfies the following condition: TL<TF.sub.i <TL+TM.sub.min for all values of i where i=1, 2, . . . , n TL is the circulated time it takes a signal to make a round of the said communication loop-network TM min is the minimum value of said first prescribed time of all n data communication units.
Claim 9
Dependent Claim
108 words
A data communication apparatus according to claim 6, comprising n (where n is an integer larger than 1) of said data communication units located in said communication loop-network, any of said data communication units having a first prescribed time defined by TM i or TM j which satisfies the relations |TM.sub.i -TM.sub.j |>TL for all values of i, j and TM.sub.i >TP for all values of i where i≠j, i=1, 2, . . . , n, j=1, 2, . . . , n TL is the circulated time it takes a signal to make a round of said communication loop-network and TP is said prescribed polarity-reversal period TP.