JPH01211099A - Gas detecting alarm device - Google Patents

Abstract

PURPOSE:To reduce the number of signal transmission cables and a construction cost by at least reporting an alarm to a central supervising part even when a trouble occurs in either a digital signal line or an alarm signal line. CONSTITUTION:When a gas leak detecting part 10 detects a gas leak, and the level of the gas leak is a constant level or above, while an indicating alarm unit 20 generates an alarm signal, the unit 20 changes an alarm state into a digital signal and sends the digital signal to a common signal transmission circuit. When the alarm is given, the alarm signal is impressed to a common alarm terminal 50, and the alarm signal passes through an alarm signal line 400 and sounds an alarm 201 of a central supervising part 200. On the other hand, a communication control part 60 successively receives the digital signal while transmission-controlling the digital signal through the common signal transmission circuit, collectively converts the digital signal into a serial digital signal, and transmits the data through a digital signal line 300 to the central supervising part 200. Thus, the increase of the number of cables used for the transmission can be eliminated, and the increase of the construction cost due to the increase of the number of the cables can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas detection and alarm device that reduces the number of signal transmission cables and construction costs.

[Conventional technology]

Conventionally, when centrally monitoring gas detection and alarm systems at industrial complexes, power plants, steel plants, automobile factories, semiconductor factories, etc., at a central monitoring unit, representative or individual alarm signals or fault status signals were transmitted via cables from the on-site monitoring equipment. It was transmitted using

[Problem to be solved by the invention]

In this case, the central monitoring unit could detect alarms or malfunctions, but it was difficult to understand the gas concentration level. moreover,
The problem is that the number of cables used to transmit individual alarm signals or fault status signals increases, which increases costs.

Furthermore, similar problems arise when a central monitoring unit centrally monitors alarms from gas leak detection alarm panels that are installed in a distributed manner.

In addition, if it is necessary to monitor the gas concentration level at the central monitoring unit, an analog signal of current value such as 4-4-2O is transmitted from the on-site monitoring device via a multi-core cable to the central monitoring unit. It is necessary to provide a receiving amplifier, an A/D converter, a multiplexer, etc., which poses a problem in that the cost of the multicore cable, its construction cost, and the cost of each component device increase.

Furthermore, a method of directly receiving signals from gas sensors by installing a receiving amplifier, A/D converter, and multiplexer in the central monitoring unit has been put into practical use, but the shape of the receiving device has become larger and the number of cables to be input is large. Not only does this increase the cost, but it also requires a CPU for the central monitoring unit.
If the CPU fails, all functions will stop. In order to notify workers at the detection site of an abnormality, there is a problem in that the alarm signal must be transmitted back from the central monitoring unit to the detection site.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a gas detection and alarm device that can communicate between each monitoring area and a central monitoring unit at low cost.

[Means to solve the problem]

The gas detection alarm device according to the present invention includes a plurality of gas sensors installed in each monitoring area, receives the output signals of these gas sensors individually, and generates an alarm signal when the output signal exceeds a certain level, and also detects the alarm state. An indicator/alarm unit converts and outputs digital signals, and the digital signals of these indicator/alarm units are sequentially received while controlling transmission via a common signal transmission line, and the digital signals are collectively converted into serial digital signals. a gas detection alarm section including a communication control unit for output and a common alarm terminal to which the alarm output of each instruction and alarm unit is applied; a central monitoring section including an alarm; a communication control unit and a central monitoring section; It is equipped with a digital signal line for connection; and an alarm signal line for connecting the common alarm terminal and the alarm.

Further, in order to configure a gas detection alarm, a plurality of gas detection alarm units each having a plurality of indicator/alarm units are connected to a signal transmission circuit while separating the power supply system using a relay adapter. A common communication control unit is provided in one gas detection and alarm unit.

(Operation) In this invention, when the gas leak detector detects a gas leak and the level exceeds a certain level, the indicator/alarm unit generates an alarm signal, and also converts the alarm state into a digital signal and sends it to the common signal transmission circuit. .In the case of an alarm, an alarm signal is applied to the common alarm terminal.This alarm signal passes through the alarm signal line and causes an alarm in the central monitoring unit to sound.On the other hand,
The communication control unit sequentially receives digital signals while controlling transmission through a common signal transmission circuit, converts them into serial digital signals, and transmits this data to the central monitoring unit via a digital signal line.

Further, a gas detection alarm device is configured by a plurality of gas detection alarm units connected by a relay adapter, and is also controlled by one communication control unit to perform predetermined operations.

〔Example〕

FIG. 1 is a block diagram showing one embodiment of the present invention.

In this figure, 100 is a gas detection alarm unit, 200 is a central monitoring unit, 201 is an alarm device such as a buzzer or lamp, and 300 is a central monitoring unit.
4 is a digital signal line, and 400 is an alarm signal line, which constitute a gas detection alarm device. Each part will be explained below.

10-1.10-2. . . . 1on (hereinafter, 10 will be simply used when referring to it generically. The same applies to other symbols) is a gas sensor, which is installed in each monitoring area. 20 is an instruction/alarm unit with input terminals 2OA,
It has a digital signal terminal 20B and an analog signal terminal 20C, each digital signal terminal 20B is commonly connected by a digital transmission line 3o, and the analog signal terminal 20
C are commonly connected through an analog transmission line 40 and connected to a common alarm terminal 50. Reference numeral 60 denotes a communication control unit which sequentially receives signals from each instruction/alarm unit 2o via the digital transmission line 3o while controlling transmission, converts all points into a serial digital signal and outputs the signal, and outputs the signal to the digital signal line 3.
Output to 00. Further, the alarm output applied to the common alarm terminal 5o is sent to the central monitoring unit 200 via the alarm signal line 400.
notification to the alarm device 201.

With this configuration, digital signals and analog signals are output from the gas detection alarm section 100 and sent to the central monitoring section 200, so that in the unlikely event that the digital signal line 300. Even if a failure occurs in either one of the alarm signal lines 400, an alarm can be sent to at least the central monitoring unit 200.

The digital signal represents the alarm state and includes various data such as gas concentration data detected by each gas sensor 10 and alarm level data determined for each monitoring area.

FIG. 2 shows details of an example of the configuration of the instruction/warning unit 20 in FIG. 1. In this figure, 21 is an amplifier whose input side is connected to an input terminal 2OA, and the gas sensor 10 is connected to this input terminal 2OA. 22 is A/D
Converter, 23 is a central processing unit (hereinafter referred to as CPU), 2
4 is a concentration indicator, 25 is an alarm display section, 26 is an address setting device consisting of switches, etc., 27 is a transmission control circuit, 28
is a relay, and 20B and 20C are digital signal terminals and analog signal terminals as in FIG.

In this operation, the output of the gas sensor 10 is amplified by the amplifier 21, then converted to a digital signal by the A/D converter 22, and input to the CPU 23. The CPU 23 determines the state of gas leakage from the input digital signal, causes the concentration indicator 24 to indicate the concentration, and when the concentration is above a certain level, displays a lamp or buzzer on the alarm display section 25, and at the same time activates the relay. 28 and outputs an anlog signal to the analog signal terminal 20C. Further, the digital signal from the CPU 23 is outputted to the digital output terminal 20B via the transmission control circuit 27.

FIG. 3 shows details of the configuration example of the communication control unit 60 in FIG. 1, where 60A and 60B are input terminals and output terminals, 61 is a transmission circuit, 62 is a CPU, and 63 is a parallel/serial converter. 64 is a transmission circuit, and 65 is a scanning point number setting device, which is used to set the number of points according to the number of instruction/alarm units 2o.

Next, the operation will be explained. The CPU 62 controls each instruction/alarm unit 20-1.
20-2. =, 2On digital signals are received, these are combined and converted into a serial signal by a parallel/serial converter 63, a transmission circuit 64 is obtained, and the signal is output from an output terminal 60B.

FIG. 4 shows another embodiment of the invention, in which the same parts as in FIG. 1 are given the same reference numerals. In this example,
The gas detection alarm unit 100 includes a plurality of gas detection alarm units 10
0A-1,100B-2゜------, 100A -
One of them is provided with a communication control unit 60, and the power supply systems are separated and connected between each gas detection and alarm unit 100A by a relay adapter 70.

According to this configuration, for example, when the gas detection alarm unit 100A is provided in each factory, power can be supplied to each factory, so additional connections etc. are extremely easy.

FIG. 5 shows an example of the circuit of the relay adapter 70 in FIG. 4, and is a left-right symmetrical circuit. Tν is a power supply terminal to which power is applied;

is a ground terminal, T, Tb is a signal terminal for inputting or outputting a signal, R,, Rb is a resistor, D,, Db is a diode, LED, LEDb is a light emitting diode, P
T a and P T b are phototransistors.

In use, when power is applied to the power supply terminal TV and a signal is applied to one signal terminal 'rb, for example, the light emitting diode LEDb emits light in accordance with this signal, and the light enters the phototransistor PT on the opposite side. therefore,
The potential at the connection point between the resistor R1 and the diode D changes according to the signal, and an output appears at the signal terminal T. In this way, the left and right circuits are optically coupled, and the power supply systems can be completely separated.

FIG. 6 shows a communication control unit 6 suitable for the embodiment of FIG.
0 is a block diagram showing another example of 0. FIG. In this diagram, 61A
, 61B is a transmission circuit, and 66 is a changeover switch. Between the transmission circuits 61A and 61B, gas detection alarm units 100A-1, 100A-2, . . . , 1 shown in FIG.
100A- is connected. , and scans the gas detection alarm unit 100A-1 via one transmission circuit 61A.
, 10OA-2, . . . Next, by switching the changeover switch 66, the gas detection alarm unit 1100A-
,..., 100A-2, 100A-1 and the like are scanned in the opposite direction. By repeating this, even if a malfunctioning gas detection alarm unit occurs, scanning can be prevented from stopping at that point.

〔Effect of the invention〕

As explained above, the present invention uses a plurality of gas sensors installed in each monitoring area, receives the output signals of these gas sensors individually, generates an alarm signal when the level exceeds a certain level, and digitally records the alarm status. An indicator/alarm unit that converts and outputs signals, and sequentially receives the digital signals of each of these indicator/alarm units via a common signal transmission line while controlling the transmission, converts the digital signals all at once into a serial digital signal, and outputs the digital signals. a gas detection alarm section including a communication control unit that controls the operation, and a common alarm terminal to which the alarm output of each instruction and alarm unit is applied; a central monitoring section equipped with an alarm; and a communication control unit and the central monitoring section connected. and an alarm signal line that connects the common alarm terminal and the alarm, so even if a failure occurs in the digital signal line or alarm signal line, the central monitoring unit will at least have only the alarm. can be conveyed.

In addition, the gas detection alarm unit can be configured as a plurality of gas detection alarm units connected by relay adapters using a common communication control unit, so it is economical even when the scale becomes large. Expansion is easy because the power supply system can be separated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing details of the configuration of the instruction/alarm unit in FIG. 1, and FIG. 3 is a block diagram showing details of the configuration of the communication control unit. 4 is a block diagram showing another embodiment of the present invention, FIG. 5 is a diagram showing an example of the relay adapter circuit in FIG. 4, and FIG. 6 is a block diagram showing another example of the communication control unit. FIG. In the figure, 10 is a gas sensor, 2o is an indicator/alarm unit, and 3
0 is a digital transmission line, 40 is an analog transmission line, 5
0 is a common alarm terminal, 60 is a communication control unit, 70 is a relay adapter, 100 is a gas detection alarm unit, 100A is a gas detection alarm unit, 200 is a central monitoring unit, 201 is an alarm, 300 is a digital signal line, 400 is the alarm signal line. Figure 1 50: Common X-report terminal Figure 2 Figure 3 Figure 5

Claims (2)

[Claims] (1) Multiple gas sensors installed in each monitoring area,
An indicator/alarm unit that receives the output signals of these gas sensors individually and generates an alarm signal when the output signal exceeds a certain level, converts the alarm status into a digital signal and outputs it, and a digital signal of each of these indicator/alarm units. a communication control unit that sequentially receives the digital signals while controlling transmission via a common signal transmission line, converts the digital signals into serial digital signals and outputs the signals; and a common alarm terminal to which the alarm outputs of the respective instruction and alarm units are applied. a gas detection alarm section comprising; a central monitoring section comprising an alarm;
A gas detection alarm device comprising: a digital signal line connecting the communication control unit and the central monitoring unit; and an alarm signal line connecting the common alarm terminal and the alarm device. (2) multiple gas sensors installed in each monitoring area;
It is equipped with an indicator/alarm unit that receives the output signals of these gas sensors individually and generates an alarm signal when the level exceeds a certain level, and also converts the alarm status into a digital signal and outputs it.The digital signals of each of these indicator/alarm units are shared. A plurality of gas detection alarm units connected by signal transmission lines, a relay adapter that connects the signal transmission lines of these plurality of gas detection alarm units while separating the power supply systems, and At least one of the gas detection and alarm units sequentially receives each digital signal of each of the instruction and alarm units through the signal transmission line while controlling the transmission, and converts each of the digital signals collectively into a serial digital signal. a gas detection alarm section including a communication control unit and a common alarm terminal to which alarm outputs of the respective instruction and alarm units are applied; a central monitoring section including an alarm; the communication control unit and the central monitoring section; A gas detection alarm device comprising: a digital signal line for connecting;