Claims
- 1. A sensor signal transmission system for transmitting serially sensor signals produced in parallel by a plurality of sensors installed at a remote station to a central control station which incorporates a power supply source,
- said central control station comprising:
- clock generating means for generating clock pulses at a predetermined timing;
- signal conversion means for converting a voltage of said power supply source into a voltage signal superposed serially with said clock pulses at said predetermined timing to generate a clock-pulse superposed voltage signal;
- start signal generating means for generating a start signal; and
- data extracting/converting means for detecting levels of a sensor state signal inputted to said central control station at said predetermined timing;
- said remote station being connected to said central control station via lines for said clock-pulse superposed voltage signal, said start signal and the ground potential and comprising:
- power generating means for generating a source voltage required for electrical energization of said sensors by smoothing said clock-pulse superposed voltage signal as received via said line for said clock-pulse superposed voltage signal;
- start signal detecting means for detecting said start signal;
- clock extracting means for extracting said clock pulses from said clock-pulse superposed voltage signal;
- clock pulse distributing means for distributing sequentially said extracted clock pulses to said sensors, respectively, in response to said start signal detected by said start signal detecting means;
- clock pulse modulation means for modulating clock pulses by sensor state signals representing the states of the sensors to which said clock pulses are distributed, respectively, to thereby generate said sensor state signal and transmitting means for transmitting said sensor state signal to said data extracting/converting means for detecting said sensor state signal by said data extracting/converting means of said central control station for evaluation processing of the states of said sensors, said transmitting means being connected to said data extracting/converting means via said lines for said clock pulse superposed voltage signal.
- 2. A sensor signal transmission system as set forth in claim 1, wherein said signal conversion means generates a DC voltage which assumes a first substantially constant level during periods except for durations of said clock pulses, said DC voltage assuming a second level differing from said first substantially constant level during the durations of said clock pulses while assuming a third level differing from said first and second levels in dependence on the output states of said sensors during the duration of said clock pulses, respectively.
- 3. A sensor signal transmission system as set fourth in claim 2, wherein said clock pulses modulated in respect to the level thereof in dependence on said output states of said sensors have the ground potential level as said third level in dependence on the output states of said sensors.
- 4. A sensor signal transmission system as set fourth in claim 2, wherein said clock pulse extracting means extracts said clock pulses from said clock-pulse superposed voltage signal through comparison thereof with a predetermined level corresponding to said DC voltage.
- 5. A sensor signal transmission system as set fourth in claim 1, wherein said clock pulse distributing means includes a shift register having a plurality of output stages connected to output circuits of said sensors, respectively, said clock pulses extracted by said clock pulse extracting means being sequentially shifted through said shift register in response to said start signal so that said clock pulses are distributed to sensor output circuits to be thereby modulated with the output states of said sensors, respectively.
- 6. A sensor signal transmission system as set fourth in claim 5, wherein each of said output stages includes a flip-flop set in response to said start signal, and a NAND gate having input terminals supplied with the set output of said flip-flop, the clock pulse extracted by said clock pulse extracting means and the output of the sensor to which said clock pulse is distrubuted and an output terminal coupled to said line for said clock pulse superposed voltage signal.
- 7. A sensor signal transmittion system as set fourth in claim 1, wherein said local station includes a plurality of blocks each including said start signal detecting means for detecting said start signal, at least one conversion unit for regenerating the clock pulses to be modulated with the output of said sensors and an end bit unit for generating said start signal to be supplied to a succeeding block.
- 8. A sensor signal transmission system as set forth in claim 7, wherein each of said blocks is provided with connectors at an input side and connectors at an output side, respectively, said connectors providing an interconnection of input and output sides of adjacent said blocks.
- 9. A sensor signal transmission system as set fourth in claim 8, wherein each of said connectors is realized through a combination of a light emission diode and a phototransistor.
- 10. A sensor signal transmission system as set fourth in claim 1, wherein said local station includes power generating means for generating from said clock-pulse superposed voltage signal electric power utilized both for electrically driving said sensors and for electrically energizing the circuit components incorporated in said local station.
- 11. A sensor signal transmission system as set fourth in claim 1, wherein said start signal generated by said start signal generating means of said central control station is imparted with a voltage level which can be discriminated from that of clock pulses to thereby allow said start signal to be transmitted through the same line as that for said clock-pulse superposed voltage signal for allowing the line dedicated for said start signal to be spared.
- 12. A sensor signal transmission system as set fourth in claim 1, wherein said data extracting/converting means of said central control station generates the binary signal representative of the sensor states by comparing the level transitions brought about in said clock-pulse superposed voltage signal by said modulation with the outputs of said sensors with a predetermined reference voltage level at said predetermined timing.
Priority Claims (1)
Number |
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62-247245 |
Sep 1987 |
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Parent Case Info
The present application is continuation-in-part application of U.S. patent application Ser. No. 241,019 filed on Sept. 2, 1988 now abandoned.
US Referenced Citations (7)
Continuation in Parts (1)
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Number |
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241019 |
Sep 1988 |
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