JPS63158692A - Wire disconnection detecting system for self-fire alarm system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an improvement in a wire breakage detection method for a self-fire alarm system.

[Background technology]

The conventional self-fire alarm system, as shown in Figure 14, has 1
A plurality of repeaters 101... are connected to one fire receiver 100, and a fire detector 102... is connected to each repeater 101.
A plurality of wires 103 are connected in parallel, and a capacitor is connected to the P: end of each wire 103 as a terminator 104.
A discharge detection circuit (not shown) is connected to the starting end of each wiring 103 to sequentially discharge the electric charge stored in the terminator 104 to determine a disconnection of each wiring 103 connected to the wiring.

FIG. 15 explains a method for detecting disconnection of each wiring in the above-mentioned self-fire alarm system, in which two wires d11.
j! A plurality of such lines are installed in parallel, with c-1n and lc forming one line, and any disconnection in the wiring that makes up each line should be connected to the starting end of each wiring 11 to ln. The contact r provided on the positive side terminals L1 to Ln
By switching between l and rn, the terminator 104 connected to each wiring 103 is charged and discharged. For example, when detecting a disconnection in wiring, the receiver 100
A control signal for executing the continuity test mode is sent out, and the repeater 101 performs the following operations for each line.

16(a) to (c) explain the operation at this time. In the first communication TI, the relay contact ri of the line to be tested is switched from the b side to the a side, and the line When the output of the discharge detection circuit (not shown) is normal, the second communication T2 is performed in synchronization with the time when the output of the discharge detection circuit (not shown) is detected, and the presence or absence of the output of the discharge detection circuit is determined. If there is an output at this time, it is determined that the wiring is normal (see (b) in the same figure), and if there is no output at this time, it is determined that the wiring is broken (see (c) in the same figure). In the third communication T3, the contact ri is switched to the b side to return to the operation mode.

However, as shown in Figure 7, the self-fire alarm system
When the common terminal of the line provided in the repeater 101 is connected as if it were shared by one common line NCC, such a disconnection detection method cannot be applied, and in such a system configuration, as shown in FIG. , when a disconnection occurs in the common line ICC, the output of the discharge detection circuit can be distinguished from the normal state due to the capacity of the fire detector 102, the wiring capacity, the terminator capacity, the abrasive resistance of the fire detector, etc. This can sometimes last for a long time to the extent that it is impossible to do so, leading to misclassifications.

Part 17 shows an electrical equivalent circuit when a smoke detector is used as the sensor 102 and a disconnection occurs in the common line 1cc, and Fig. 18 shows a contact-operated heat sensor as the sensor. The figure shows an electrical equivalent circuit when using
When switching n from side b to side a, the sensor of the other line (
Mainly smoke detectors (heat detectors are excluded because they operate as contacts) and test line detectors via terminators.

This causes problems such as charge flowing into the terminator and the output of the discharge detection circuit becoming longer than normal.

[Purpose of the invention]

The present invention has been proposed to solve the above problems, and can be used without misjudgment even in a self-fire alarm system in which the lines provided in each repeater are shared by one common line. The purpose is to provide a detection method.

[Disclosure of the invention]

The present invention proposed to achieve the above object is a wire breakage detection method used in a self-fire alarm system in which a terminator is configured by connecting a capacitor and a resistor in parallel,
This is carried out by sequentially performing the following operations (a) to (f).

(a) Voltage is supplied from the starting ends of all the wiring provided in each of the repeaters to charge all of the terminators.

(b) Cut off the supply of the voltage to the wiring whose disconnection is to be detected, connect the starting end of the wiring to a discharge detection circuit provided in the repeater, and discharge the charge stored in the terminator.

(c) Determining whether or not there is an output from the discharge detection circuit within the time period during which the terminator discharges when the wiring is normal.

(d) When the above wiring is normal, the above P! It is determined whether or not there is an output from the discharge detection circuit within the time when the terminal device completes discharge.

(e) After a predetermined period of time after the determination in (f) above, it is determined whether or not there is an output from the discharge detection circuit.

(f) The present invention is characterized in that it is determined whether or not there is a disconnection in the wiring based on the determination results of (c), (d), and (e) above.

〔Example〕

The present invention will be explained below with reference to the accompanying drawings. When implementing the method of the present invention, the terminator A connected to the end of the line provided in each repeater is configured by connecting a resistor R to a capacitor C in parallel. The one shown in Figure 1 is used.

In Fig. 1, S is a fire detector, 11-in is the positive side wiring of each line connected to terminals 1-Ln of the repeater, and 7! cc is one negative common line connected to the common terminal CC of the repeater.

The starting end of each line 11 to fn is a relay contact r l -rn
The b side of each of the relay contacts r1 to rn is connected to a positive power source (not shown), and the other a side is connected to a discharge detection circuit B...

Fig. 2 shows the configuration of the discharge detection circuit B, in which resistors R1 and R2 are provided at the base of the transistor TR to define the discharge time of the charge charged in the capacitor C to the terminator, and a Zener diode is connected to the terminal. ZD defines the drive voltage of transistor TR. When the capacitor C is discharged to the terminator, the transistor TR becomes conductive.
The output is input to a photocoupler PCI (not shown), and is sent as a reply signal from the repeater to the receiver.

Next, a specific embodiment of the present invention will be described. In the present invention, a receiver sequentially calls repeaters using a so-called multiplex transmission method, and sequentially transmits signals to a plurality of lines installed in the called repeater. A disconnection test can be performed. In such a disconnection test, the repeater connects the relay contacts r l -s-r n
The following continuity test mode is executed by sequentially switching from the A side to the A side. That is, in this continuity test mode, the following signals are exchanged between the receiver and each repeater to perform disconnection detection according to the present invention. When the wiring is normal, the transistor of the discharge detection circuit B becomes 1 due to the discharge of the charge stored in the capacitor C of the terminator A.
The conduction time shall be approximately 8 to 35 msec.

In the first communication T1 from the receiver to the repeater, the relay contact r1 of the test time vA (for example, the first) is connected to b
Switching from side to a side, second and third communications T2. T3
View the output of discharge detection circuit B.

That is, in the second communication T2, if the transistor TR is determined to be non-conductive, the wiring is in the state of disconnection I, that is, the positive side wiring 11 is determined to be disconnected (see FIGS. 3(b) and 4). If the transistor TRI is conductive, the conduction state of the transistor TRI is further checked at the third communication T3.

At this time, if the transistor TRI is non-conductive, it is determined that the discharge of the capacitor C of the terminator A has been completed, and it is determined that there is no disconnection and it is normal (see Figure 3 (c)). If the transistor TRI continues to conduct, the wire will be disconnected■
In other words, it is determined that due to the disconnection of the common line βcc, current flows into the discharge detection circuit B through the resistor R connected in parallel to the capacitor C of the terminator A (see FIG. 3(d) and FIG. 5).

In the fourth communication T4, the relay contact rl is set to the a side to switch to the normal operation mode.

The above operation is repeated for each line provided in each repeater, and the presence or absence of a disconnection in each wiring is detected. Table 1 shows the criteria for determining the presence or absence of wire breakage when the method of the present invention is implemented.

Table 1 The method of the present invention as described above is based on the following principle.

In other words, when each line is normal without any disconnections, in the operating mode in which the relay contact ri is held on the b side and a voltage of, for example, 24V is supplied and held to each wiring Ai, the capacitor C to the terminator is charged and the continuity test is performed. Contact ri in mode
When P is switched to the a side, the charge charged in the capacitor C of the terminal A is discharged to the discharge detection circuit B, so if the discharge time at this time is set in advance, it will be possible to By checking the presence or absence of an output from the discharge detection circuit B, it can be determined whether or not a disconnection has occurred.

Therefore, the first reference to check the output of the discharge detection circuit B is the timing when the output is obtained from the discharge detection circuit B when the wiring is normal, and if there is no output from the discharge detection circuit B at that time, the terminator Capacitor C is in a state where it cannot be charged.
In other words, the plus side wiring βi is determined to be in a disconnected state (see FIG. 4).

The second reference of the discharge detection circuit B is performed when the discharge of the capacitor C to the terminator is completed and the output of the discharge detection circuit B disappears when the wiring is normal.

However, this determination at the time of reference has a problem when the common line is broken as described in [Background Art], so in the method of the present invention, each terminator A has a configuration in which a resistor R is connected in parallel to a capacitor C. If a break occurs in the common line fcc, a circuit is configured in which current 1 flows into the discharge detection circuit B from another line to which voltage is supplied via the resistor R. There is. FIG. 6 is a diagram explaining the operation of the terminator A at this time. As a result, the common line 11c
If there is a disconnection in c, the output of discharge detection circuit B will always be present, whereas in normal conditions, P and terminal A
Since the discharge of the charge stored in the capacitor C is completed and the output of the discharge detection circuit B disappears, this difference makes it possible to reliably determine the disconnection.

Next, another detection method effective for detecting a disconnection will be described.

Similar to the present invention described above, this method also solves the problems in the fire alarm system shown in FIG. 7 in which one common vAICC is provided in the repeater line.

Figure 8 shows an example of the configuration of a system using this method.The fire detector S connected to each line has diodes DI-Dn connected in the forward direction (the anode is on the positive side of the power supply). (provided so as to be located). Such a diode is connected to its base in a real fire detector.

The procedure of this method will be explained with reference to the time chart shown in FIG. When the wiring of the line is normal, the output of the discharge detection circuit B is assumed to continue for about 113 msec to 35 msec.

In the first communication T1 from the receiver to the repeater, the relay contact r1 of the line to be tested (for example, the first line) is switched from the b side to the a side, and in the second communication T2, the output of the discharge detection circuit B is changed. I see. Next, in the third communication T3, the relay contact r1 is returned from the a side to the b side, and in the fourth communication T4, the relay contact r1 is returned again from the b side to the a side, and the fifth communication T5 is performed.
Check the output of discharge detection circuit B again.

Table 2 shows the judgment criteria when implementing this method.

Table 2 This method is based on the following principle.

That is, when explained with reference to Figures 10 to 13,
When the wiring is normal and there is no disconnection, the capacitor C1 forming the terminator repeats charging and discharging every time the relay contact r1 is switched (FIG. 10(a)).

(see (b)), but when the positive side 11 of the wiring is the Ur wire (
Since the capacitor CI is not charged at the disconnection I), there is no output from the discharge detection circuit B (see FIG. 11).

In addition, if the common line 1cc is disconnected as shown in Fig. 12 (indicated by disconnection ■), the capacitor C1 charged by the operation of the first communication T1 is connected to the fire detector S...
・Since the wraparound through the capacitor C1 is blocked by the diode DI... during the second communication T2.
is charged (see Fig. 13(a)), and since no discharge path is formed after that, there is no output from the discharge detection circuit B at the fifth communication T5 (see Fig. 13(b)).
(Reference).

〔Effect of the invention〕

As can be understood from the above explanation, according to the method of the present invention, the wiring can be adjusted even for a self-fire alarm system configured in which the negative side wiring of each line connecting the fire detector is connected with one common line. Since disconnections can be detected without error, the wiring configuration of the fire reception system can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of a terminator used in the method of the present invention, FIG. 2 is a configuration example of a discharge detection circuit, and FIG.
The figure is an explanatory diagram of the operation of the method of the present invention, Figures 4 to 6 are explanatory diagrams of an example in which a wire is broken, and Figure 7 is a configuration diagram of a self-fire alarm system to which the method of the present invention can be applied. The figure is a connection configuration diagram of a fire detector used in another disconnection detection method, Figure 9 is an explanatory diagram of the operation of the disconnection detection method, and Figure 10 (a).
b) is an explanatory diagram of the operation when the wiring is normal, Figure 11 is another diagram when the positive side wiring is disconnected, Figure 12 is another diagram when the common line is disconnected, Figure 13 (a), ( b) is an explanatory diagram of the principle of another disconnection detection method when the common line is disconnected; Figure 14 is a diagram showing the configuration of a conventional self-fire alarm system;
The figure is a wiring configuration diagram of a fire detector, Figure 16 is an explanatory diagram of the operation of the conventional disconnection detection method, Figure 17 is a separate diagram when a disconnection occurs in the common line, and Figures 8 and 19 are the same. i1! ! A diagram illustrating the principle when a break occurs in the wire is shown. (Explanation of symbols) 100... Receiver 101... Repeater 102... Fire detector A... Terminal C... Capacitor R...) Resistor B... Discharge detection circuit

Claims (1)

[Claims] (1) Connect multiple repeaters to the fire receiver, provide multiple lines with fire detectors connected to each repeater, and connect a capacitor and a resistor in parallel to the ends of each of these lines. This is a wire breakage detection method implemented in a self-fire alarm system configured by connecting terminators consisting of: (b) Cut off the supply of the above voltage to the wiring whose disconnection is to be detected, connect the starting end of that wiring to a discharge detection circuit installed in the repeater, and charge the above terminators. (c) determine whether or not there is an output from the discharge detection circuit within the time period in which the terminator discharges when the wiring is normal; (d) discharge the electrical charge when the wiring is normal; (e) After a predetermined period of time after the determination in (d) above, determine the presence or absence of an output from the discharge detection circuit within the time when the device completes discharge. and (f) above (c
A wire breakage detection method for a self-fire alarm system, characterized in that the presence or absence of a wire breakage is determined based on the determination results of ), (d), and (e).