JPH0271632A - Alarm holding circuit - 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] [Summary of the Invention] This invention relates to an extremely simple alarm holding circuit that holds various alarms in an alarm monitoring unit of a telephone, data transmission and switching device, and which is released by a maintenance person using a reset switch. The purpose is to provide an alarm holding circuit that has a low cost structure, long life, and easy maintenance.It operates in response to a signal from the device that indicates the occurrence of a fault, and has an output that sends an alarm signal to the alarm display section. and a holding electronic relay that operates upon receiving a signal notifying the occurrence of the fault to create a holding circuit for the output electronic relay and releases the holding circuit when the reset switch is pressed. Configure to run on power.

[Industrial Application Field] The present invention relates to an alarm holding circuit that holds various alarms in an alarm monitoring section of a telephone, data transmission and switching device, and which is reset by a maintenance person using a reset switch.

[Conventional technology]

Alarm monitoring unit (equipment) for transmission and switching equipment for telephone calls, data, etc.
The system is equipped with an alarm holding circuit that holds alarms generated in the transmission and exchange equipment, allows a maintenance person to perform repair processing after seeing or hearing the alarm, and releases the alarm holding after processing. Examples of the circuit are shown in FIGS. 3 and 4.

In FIG. 3, reference numeral 10 denotes a transmission/switching device section, and SW1 is a switch that closes when a fault occurs in the device, such as a fuse blowout. Although not shown, there are a plurality of switches of this kind, which are attached to each part of the device and operate when a failure occurs in that part. Reference numeral 12 denotes an alarm monitoring unit having a relay RL and a reset switch SW2. rll and r12 are contacts of relay RL, rj21 is for alarm, and r12 is for self-holding.

Now, when a failure occurs in the device section 10 and switch SW1 is closed, relay RL is energized and contacts r11, r/! Close 2. When contact rit2 closes, r12-3W2-RL
--Vcc path is established and relay RL continues to be energized even if switch SWI is opened.

When the contact rj21 closes, a lamp on the alarm display section (not shown) lights up, and the maintenance person sees this and presses the switch SWI.
For example, find out if the power supply fuse of the XX device has blown. The maintenance personnel who learned of the failure carried out the recovery process, and after recovery,
Press switch SW2. This opens the holding circuit and de-energizes the relay RL, and since at least at this point the switch SWI is open, it cannot be re-energized by the switch SW1, so the lamp of the alarm display is extinguished.

The self-holding of the relay RL by the contact r12 is effective in notifying the occurrence of a fault even if the fault is temporary and the switch SWI opens immediately after closing. This third
The circuit shown in the figure is used, for example, in a PCMMUX (PCM multiplexing device).

FIG. 4 uses a memory instead of a relay. 1
4 is a level conversion circuit, which is connected to the switch S from the device section 10.
Converts the earth signal generated by the WI closing to a level suitable for alarm detection. The alarm detection unit 16 receives the level-converted earth signal and writes the fault information into the memory 18. This is read out and sent to an alarm display section (not shown).
For example, a lamp may be lit to notify the user of the occurrence of a failure. The maintenance person sees this and performs the recovery process, and then switches SW2.
Press. As a result, the fault information written in the memory 18 is erased, and the lamp of the alarm display section is turned off. In addition, 20
is a power supply section that supplies power to each section of the alarm monitoring section 12.

(Problems to be Solved by the Invention) However, the relay type as shown in FIG. 3 has problems such as short mechanical life and high cost.

Further, a circuit using a memory as shown in FIG. 4 is large in scale and requires additional circuits such as a power supply, which is also disadvantageous in terms of cost.

SUMMARY OF THE INVENTION It is an object of the present invention to improve these points and provide an alarm holding circuit which has an extremely simple structure, is therefore low cost, has a long life, and is easy to maintain.

[Means for Solving the Problems] As shown in FIG. 1, in the present invention, the alarm monitoring section 12 is provided with a holding electronic relay 22 and an output electronic relay 24. These electronic relays operate with the existing power supply -Vcc, and the holding electronic relay 22 is released from holding when the reset switch SW2 is pressed and released.

As is the case throughout all the figures, the same parts as in other figures are given the same reference numerals, so 10 is a device section, and SW is a switch that is attached to each part of the device and closes when a failure occurs in that part.

[Effect]

In this circuit, when a fault occurs in the part of the device section 10 corresponding to the switch SWI, the switch SWI closes, thereby operating the electronic relays 22, 24, and the relay 24 causes the fault to occur in the part of the device section IO corresponding to the switch SWI. The occurrence of this is notified to an alarm display section (not shown), and a lamp, for example, is turned on. Relay 22 also completes the path to ground and is self-sustaining, allowing output electronic relay 24 to remain energized even when switch SWl is open.

When the maintenance person sees the lighted lamp on the alarm display section and performs the recovery process, and presses the reset switch SW2 when the process is completed, the electronic relay 22 is restored, and then the electronic relay 24 is deenergized to recover), and the alarm display section The lamp will turn off.

In this circuit, the relay is not a mechanical relay but an electronic relay such as a transistor, so it has a long life, low order, and small size. Further, the existing power supply -Vcc can be used as a power supply, and a special power supply such as the power supply 20 in FIG. 4 is not required.

〔Example〕

FIG. 2 shows an embodiment of the present invention. As shown in the figure, the output electronic relay 24 is composed of a photocoupler 24a, and the holding electronic relay 22 is composed of a photocoupler 22a and a transistor circuit 2.
It consists of 2b.

In this circuit, when a fault occurs and the switch SWl is closed, the light emitting diode of the photocoupler 22a emits light, the photodiode becomes conductive, and the base current of the transistor Q flows. Therefore, the transistor Q is turned on and Q-3W2-
22a (continues to be in the on state even if the switch SWI is turned off). The path of Q-3W2 also serves as a holding circuit for the photocoupler 24a, and the switch SWI
Even if the photocoupler 24a is opened, the light emitting diode of the photocoupler 24a emits light and the phototransistor continues to be conductive. Therefore, the lamp in the alarm display section continues to light up.

However, when the reset switch SW2 is pressed and opened, if the switch SWI is open, the energizing circuit of the photocoupler 22a is opened and its light emitting diode stops emitting light, and as a result, the base current of the transistor Q is cut off and the transistor Q is turned off. become. Therefore, the energizing current is also cut off from the photocoupler 24a, and its light emitting diode stops emitting light, and the photodiode is turned off. Therefore, the lamp on the alarm display section goes off.

The existing power supply -Vcc is, for example, -48V, and the alarm display section is composed of a TTL circuit, so it needs to be insulated to prevent high voltage from being applied, but using a photocoupler can easily and reliably perform this insulation. be able to.

〔Effect of the invention〕

As explained above, according to the present invention, the alarm holding circuit, which conventionally used a mechanical relay, had low reliability and was expensive, can be made highly reliable and low-cost by using a long-life electronic relay. Moreover, it is not necessary to add a power supply device, and there are advantages such as a reduction in the mounting area.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram of the present invention, FIG. 2 is a circuit diagram showing an embodiment of the present invention, and FIGS. 3 and 4 are circuit diagrams showing a conventional example. FIG. 1 is a diagram showing the principles of the present invention. In FIG. 1, 10 is a device section, 12 is an alarm monitoring section, 22 is a holding electronic relay, 24 is an output electronic relay SWI is a switch, and SW2 is a reset switch. Applicant: Fujitsu Ltd. Representative Patent Attorney Hoki Aoyagi Figure 2 is a circuit diagram showing an embodiment of the invention.

Claims (1)

[Claims] 1. An output electronic relay (24) that operates upon receiving a signal indicating the occurrence of a fault from the device section (10) and transmitting the alarm signal to the alarm display section; It operates to create a holding circuit for the output electronic relay, and reset switch (SW2)
An alarm holding circuit comprising: a holding electronic relay (22) that releases holding when is pressed; and these electronic relays are operated by an existing power source.