JPH0287762A - Current monitor system - Google Patents

Abstract

PURPOSE:To allow the master set side to monitor the operating state of a slave set by adopting the constitution such that the master set monitors a current flowing to a line even when the slave set receives external power supply. CONSTITUTION:With a circuit of a changeover device 10 of a slave set 2 thrown to the position of contact (b), if power required for the slave set 2 is obtained from an external power supply connecting to a external power terminal 11, a detector 8 identifies the power supply state from the external power supply and closes the contact of the line switching section 9 when the state is normal. Thus, a dummy load 7 is connected to a line 3 and a current flows to a closing circuit from the power supply 4 of the master set 1 including the load 7. If power is not normally supplied from the external power supply, since the detection section 8 opens the contact of the switch section 9, the current on the line 3 is disappeared. the monitor section 5 detects the state above, then the master set 1 recognizes the state of the slave set 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is constructed such that a main device and a slave device are connected to each other via a wired line and communicate with each other, such as a main device in a key telephone and a telephone set. Regarding a method for monitoring the operational status of a child device by a parent device in a system that supplies power for the operation of the child device through the wired line, in particular, it is possible for the child device to receive power supply from sources other than the parent device. This pertains to monitoring means when it has such functions.

[Conventional technology]

PIS 3 is a diagram showing an example of the configuration of a conventional current monitoring system, in which 51 is a parent device, 52 is a child device, 53 is a transmitting/receiving section of the parent device, 54 is a monitoring section, 55 is a 7 Otokabufu, 56
Current detection resistor, 57 power supply, 58 communication line, 59
60 is a rectifier circuit, 61 and 62 are respective power supply circuits, 63 is a switch for switching the power supply, and 64 is an external power input terminal such as an AC adapter.

In the figure, the transmission/reception section 53 of the parent v device 51 is connected to the line 58.
Communication is performed with the transmitting/receiving section 59 of the child device via. At the same time, power is supplied from the power supply 57 to the power supply circuit 61 of the slave device via the communication line 58, and each part of the slave device operates with the power supplied from the power supply circuit 61.

At this time, the monitoring unit 54 of the parent device 51 monitors the voltage across the current detection resistor 56 via the Oto coupler 55, and determines whether the child i The system is designed to allow you to know the operating status of the equipment.

[Problem to be solved by the invention]

As described above, when power is supplied from the parent device to the child device, it is possible to detect a failure in the child device by monitoring the supply current flowing to the child device in the parent device.

However, as the distance between the parent device and the child device increases, the electrical resistance of the line increases, making it impossible for the child device to receive a 2ft power supply from the parent device. Therefore, as shown in Figure #3, it was necessary to provide a means for supplying power to the slave device from an external power source such as an AC converter, thereby supplying power. In this case, power is not supplied from the parent device to the child device, and no current flows through the circuit that includes the current detection resistor, so the problem is that it is impossible for the parent device to detect a failure in the child device. was there.

In order to solve the above-mentioned drawbacks, the present invention provides that even when the power to the child device is not supplied from the parent device but from an external power source such as a battery or an AC power supply,
The purpose of this invention is to provide a means by which a parent device can monitor the operating status of a child device.

[Means to solve the problem]

According to the invention, the above objects are achieved by the means specified in the claims.

That is, the present invention provides a system in which a parent device and a child device are connected by a line and communicate between the devices, and when the parent device is supplying power to the child device through the line, the supply of power is In a system configured to monitor the current in the circuit to determine whether power is being supplied normally to the child device, when the child device receives power from a source other than the parent device, means for connecting a dummy load circuit to a circuit receiving power supply, and a means for connecting a dummy load circuit to a circuit receiving power supply, and a means for connecting the dummy load circuit to a circuit receiving power supply, and a means for connecting the dummy load circuit to a circuit that receives power from a source other than the parent device; This current monitoring method is provided with a means for opening the pseudo load circuit when a state in which the pseudo load circuit is not set is detected.

[For production]

FIG. 1 is a diagram showing the basic configuration of the present invention. 6 In the same figure, the parent device! ! 1 is configured to supply power necessary for the operation of the slave device 2 to the slave device 2 through the line 3 from the power source 4, and at the same time, the load current is monitored by the monitoring section 5.

On the other hand, the child device 2 receives the power necessary for the operation of the internal circuit 6 from the parent device 1 via the line 3, or receives power from the external layer a.
It has a function of being able to switch whether or not the power is received from an external power source such as an AC feeder via the switch 11.

When power is supplied from the master device a1 to the slave device 2, the switching device 10 switches the circuit to the a contact side, and the monitoring unit 5 monitors the current flowing from the power source 4 to the internal circuit 6. Identifies whether the child device is operational or not.

On the other hand, the circuit of the switch 10 is switched to the b contact side,
Child device i! When obtaining the power necessary for operation 2 from an external power supply connected to the external power supply terminal 11, the detection unit 8 identifies the state of power supply from the external power supply, and if it is normal, opens or closes the circuit. Close the contacts of part 9.

By this, the line v! A pseudo load 7 is connected to the power source 3, and a current flows from the power source 4 to a closed circuit including the pseudo load 7.

If power is not normally supplied from the external power source, the detection unit 8 opens the contacts of the circuit opening/closing unit 9, so the line 3
The upper current disappears.

By the monitoring unit 5 detecting these states, the parent device 1 can know the state of the child device 2.

〔Example〕

In the present invention, as means for detecting whether power is being normally supplied to the slave device from an external power source, a method of detecting the voltage or current, a method of confirming the normality of circuit operation, or a method of detecting the normality of circuit operation, or One possible method is to make a judgment based on the logical product of the former and the latter.

Figure 1lS2 is a block diagram of an embodiment of the present invention,
Among the above methods, an example is shown in which opening and closing of the pseudo load circuit is controlled by the AND of the voltage of the external power supply and the normality of operation of the slave device control unit (specifically, a specific signal output). .

First, the route of the audio signal will be explained based on the same figure.The audio signal sent from the transmitting/receiving section 13 of the parent device 12 passes through the transformer 14 and the DC cut capacitor 15.
The signal is then sent to the connection terminal 16. This signal is input to the child device 18 via the cable 17, and the capacitor 1
9. Transmission/reception of slave device 18 via transformer 20 ff1S2
1 is input.

On the other hand, the audio signal sent from the transmitting/receiving section 21 of the child device 18 passes through the transformer 20 and the capacitor 19 to the connecting terminal 2.
2. This signal is input to the parent device 12 via a cable 17, and then via a capacitor 15 and a transformer 14 to the A! ! 12 transmission/reception 81S13.

As described above, audio signals can be exchanged between the parent device 12 and the child device 18.

Next, to explain the supply of power to the child device 18, when the power to the child device 18 is supplied from the parent device 12, the current detection resistor 25, Power is supplied to the child device connection terminal 16 via the first and second coils 24, and further from the connection terminal 22 via the cable 17. This power is input to the power supply circuit 29 via the Chirok coil 26, the rectifier circuit 27, and the a contact point of the switch 28. The output of the power supply circuit 29 is supplied to each part of the child device by a switch 30.

On the other hand, when power is supplied to the child device by a battery or AC7 gupta, the switches 28 to 30 are switched to the b contact side, and the parent device 1
Power is supplied to the child device in the same way as in the case described above, but in the child device, power is supplied from the parent device 12 to the child device 2.
6. Dummy resistor 31 via rectifier circuit 27 and switch 28
Power is supplied to the 7-oto coupler 32.

Further, the power input from the AC input terminal 23 is input to the power supply circuit 34 through the switch 30, and
4 is supplied to each part of the child device via the b contact of the switch 30.

On the other hand, from the output of the power supply circuit 34 to the signal line 35 and the control unit 36
Failure information (indicated by the letter A in the figure) is input to an AND circuit 38 via an inverter 37. Here, if the control unit 36 determines that the operation of the circuit of the child device 18 is normal, that is, there is no failure, the failure information A becomes a low state (hereinafter referred to as rLJ), and the output of the inverter 37 becomes a high state ( (hereinafter referred to as rHJ).

In addition, since the output of the power supply circuit 34 is also rHJ, the output of the AND circuit 38 is rHJ, so the 7-oto coupler 3
A current flows to the input side of No. 2, and the output of No. 7 Otocoupler 32 becomes conductive.

Therefore, current flows through the dummy resistor 31. Here, if the control unit 36 determines that the operation of the circuit of the child device is abnormal, the failure information A becomes rHJ, so the output of the inverter 37 becomes rLJ, and the output of the AND circuit 38 also becomes rLJ. Therefore, no current flows through the input terminal of the seven-way automatic coupler 32, and therefore the output of the seven-way automatic coupler 32 is cut off.

Furthermore, when the voltage is no longer applied to the AC converter input terminal 33, the output voltage of the power supply circuit 34 becomes rLJ.
The signal #i35 becomes rLJ, the output of the AND circuit 38 becomes rLJ, and the output of the 7-oto coupler 32 is similarly cut off.

As described above, if the slave device fails or if power is no longer supplied to the AC converter input terminal 33, no current will flow through the dummy resistor 31.

Next, a method for detecting a failure in the child device 18 from the parent device 12 will be explained. When a current flows from the power supply B section 23 for the child device to the child device 18, a voltage is generated across the resistor 25 for current detection. occurs, a current flows to the input side of the 7 Otokabura 39,
The output of the 7-otokobura 39 becomes conductive.

Therefore, since the output B of the photocoupler becomes rLJ, rLJ is added to the failure detector 40 of the parent device 12, and it is determined that the child device is operating normally.

Here, if power to the child device is supplied from the parent device 12, if the circuit of the child device breaks down and current from the parent device no longer flows, or if the power source of the child I & If the child device's circuit breaks down and the current from the parent device 12 stops flowing while the power is being input from an AC power source, or if the power to the child device is being input from a battery or AC power source, etc. If power is no longer supplied from the battery or AC power source, etc., no current will flow from the power supply 23 for the child device, so no voltage will be generated across the current detection resistor 25, and the 7 Otokabura 39 Current no longer flows to the input side of.

Therefore, the output of the 7t Tokabura 39 is cut off, so
The output of the photocoupler becomes rHJ, and rHJ is added to the failure detector 40 of the parent device 12, indicating an abnormality in the child device or the cable 17 connecting the parent device 12 and the child device 18.
Abnormalities can be detected.

In addition, although the above embodiment describes a case where a power supply is superimposed on a communication path for signal transmission, the present invention is not limited to this, and a case where a communication line and a power supply line are provided separately. It can also be applied to

〔Effect of the invention〕

As explained above, according to the present invention, even when the slave device is receiving power supply from an external commercial N source, the parent device monitors the current flowing through the line, thereby preventing the malfunction of the slave device. There is an advantage that it is possible to detect a power outage of an external commercial power source, a disconnection of a line between a parent device and a slave device, etc.

[Brief explanation of drawings]

The vS1 diagram is a diagram showing the basic configuration of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, and the pPSs diagram is a diagram showing an example of the configuration of a conventional current monitoring system. 1 12 ...... Child device, 4 ... Power supply, 6 ... Internal circuit, 8 ... Detection section, Section, 10 ・...External power supply terminal, transmitting/receiving section, 1 1519...22 ...Connection terminal, pull, 23 ...24 26...25・・・・・・Resistor, path, 28 29 34 ・・・・・・ dummy resistor, tokabufu, 33 power terminal, 35 ・・・・・・control unit, 3 38 ....AND circuit, parent device, 2 18 3 ....line, 5 ....monitoring section, 7 ....pseudo load, 9 .... Circuit opening/opening switch, 11 4.20... Transformer, capacitor, 16 17... Power supply section for cable device, 1 coil, 27... Rectifier port 30... Switch, 1! Source circuit, 31... 32.39... 7 O... AC Agebuta input r "Odd coincidence, 36 7...... Inverter, 40...... Failure Detector

Claims (1)

[Scope of Claims] A system in which a parent device and a child device are connected by a line and communication is performed between the two devices, and when the parent device is supplying power to the child device through the line, the power is supplied to the child device. In a system configured to determine whether power is normally being supplied to a slave device by monitoring the current in the circuit,
When the child device receives power from a source other than the parent device, means for connecting a pseudo load circuit to the circuit receiving power from the parent device; A current monitoring system characterized in that a load circuit forms a closed circuit, and means is provided for opening the dummy load circuit when a state in which the power is not being normally supplied is detected.