Separation type detector with addressed selection

• US 4,701,625 A
• Filed: 07/03/1986
• Issued: 10/20/1987
• Est. Priority Date: 09/02/1985
• Status: Expired due to Term

• Current Assignee: Nittan Co. Ltd. (Old) (Secom Company Limited)
• Original Assignee: Nittan Co. Ltd. (Old) (Secom Company Limited)
• Inventors: Kimura, Tetsuo
• Primary Examiner(s): Nelms, David C.
• Application Number:
  US06/881,606
• Time in Patent Office: 474 Days
• Field of Search: 250/221, 250/222.1, 250/573, 250/574, 250/575, 340/504, 340/505, 340/516, 340/534, 340/555, 340/556, 340/557, 340/630
• US Class Current: 250/573
• CPC Class Codes: G08B 26/002 only replying the state of the sensor

Abstract

A separation type detector includes at least one pair of transmission and reception units connected through a transmission line, detects environmental abnormality according to changes in pulse beams or ultrasonic waves transmitted from the transmission unit and received by the reception unit, and sends an abnormal signal to a central monitor through the transmission line. The transmission and reception units respectively include transmission circuits assigned with an identical address. The pair of transmission and reception units are synchronously operated in response to a command from a central monitor.

Claims

1. A separation type atmospheric detector system, comprising:

a central monitor connecting to a transmission line;

detection means connected to the transmission line for detecting an atmospheric abnormality according to changes in at least one pulse transmitted from a transmission unit to a reception unit of the detection means, said detection means sending an abnormality signal to the central monitor through said transmission line;

the transmission unit and reception unit of the detection means comprising an associated pair in proximity to one another and each of the transmission and reception units having means for assigning a same given address to each unit of the pair; and

said transmission unit and reception unit each having means for being synchronously operated with respect to one another in response to a command from said central monitor.

2. A detector according to claim 1 wherein said transmission unit has means for transmitting a light pulse beam and said reception unit has means for receiving said light pulse beam.

3. A detector according to claim 1 wherein said transmission unit includes a signal converter means with a serial/parallel circuit means for converting a serial access signal from said central monitor to a parallel signal, and for outputting an address signal and a command signal;

a preset address generator means for generating the given address assigned to said transmission unit;

an address comparator means for receiving the address signal from said signal converter means and the given address from said preset address generator means and outputting a coincidence signal when the address signal coincides with the given address; and

a command identification circuit means for identifying a command given presence of the coincidence signal.

4. A detector according to claim 3 wherein said transmission unit further includes a light emitting means, a monostable multivibrator means connected to receive the coincidence signal and provide an output in response thereto, and a drive means for driving said light-emitting means in response to said output signal from said monostable multivibrator means.

5. A detector according to claim 3 wherein said reception unit includes a signal converter means having a serial/parallel circuit means for converting a serial access signal from said central monitor to a parallel signal, and for outputting an address signal and a command signal;

a preset address generator means for generating the given address assigned to said transmission and reception unit pair;

an address comparator means for receiving the address signal from said signal converter means and the given address from said preset address generator means and outputting a coincidence signal when the address signal coincides with the given address;

a command identification circuit means for identifying the command upon occurrence of the coincidence signal; and

a response signal generator means for sending back a response signal to said signal converter means.

6. A detector according to claim 5 wherein said reception unit further includes a light-receiving means for receiving the pulse beam from a light-emitting means from the transmission unit, amplifier means for amplifying an output from said light-receiving means, and a discriminator means for receiving outputs from said command identification circuit means and said amplifier means, and for supplying a discrimination signal to said response signal generator means.

7. A detector according to claim 1 wherein the transmission unit has means for providing a pulse beam which is a modulated pulse beam.

8. A detector according to claim 7 further including a demodulator means connected between an amplifier means and a discriminator means in said reception unit.

9. A detector according to claim 1 wherein said detecting means transmission unit emits pulses which are ultrasonic waves.

10. A separation type atmospheric detector system, comprising:

a transmission line connecting to a central monitor;

a plurality of detection means, each of which is formed of an associated transmission unit and reception unit pair, and each of which is connected to the transmission line;

said detecting means detecting atmospheric abnormality according to changes in pulses transmitted from said transmission unit to said reception unit through atmosphere being checked;

said detecting means being adapted to send an abnormality signal to said central monitor through said transmission line as a result of a detected atmospheric abnormality;

said transmission unit and said reception unit each having preset address generator means which generate a same given address for the reception unit and the transmission unit of the pair; and

address comparator means associated with each transmission and reception unit of the pair for generating a coincidence signal for operating the transmission unit to send said pulse and operating the reception unit to receive said pulse synchronously with one another in dependence upon the transmission and reception units each receiving said given address over said transmission line from said central monitor.

11. The system according to claim 10 wherein the transmission unit contains means for transmitting a pulse which is one of the pulses light or sound and which has a predetermined pulse length, and wherein said associated reception unit has means for detecting a length of the received pulse as a measure of atmospheric abnormality.

12. The system according to claim 10 wherein both the transmission unit and the reception unit each have a command identification means for identifying a command received from the central monitor via the transmission line such that the transmission unit and reception unit of a given pair identify the same command and thus operate compatibly and synchronously with one another relative to carrying out the command.

13. The system according to claim 12 wherein the command identification means identify either a response data request command or a test command, said command identification means for said test command changing operating parameters suitable for testing the transmission unit and reception unit.