JPS604343A - Switching control circuit with malfunction preventing means - Google Patents

Abstract

PURPOSE:To prevent a switching control circuit from switching a device to the device, which is connected to an abnormal power supply part, in accordance with an erroneous switching command signal from the device having the abnormal power supply part by providing a power supply abnormality detector and an inhibiting circuit. CONSTITUTION:In case of the abnormality of power supply where the power source voltage of a device #1 is lowered gradually, the device #1 transmits two signals of a switching command signal #1-CP and a switching request signal #1-CR to the external. At this time, an amplifier AMP-3 in a power supply abnormality detector #1-PD detects that the power source voltage of the device #1 is lower than a normal voltage VL1, and the terminal 2 of a gate circuit G4 is set to ''1'' by the output of this amplifier AMP-3, and therefore, the terminal 1 of an inhibiting circuit G3 is set to ''1'', and the switching command signal #1-CD applied to the terminal 2 cannot pass through the inhibiting circuit G3. As the result, the switching from a device #0 to the device #1 is not performed because the state of a flip flop D-FF is held as it is.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a switching control circuit with malfunction prevention, and more particularly to a switching control circuit with malfunction prevention used in duplex component equipment in a satellite communication device.

(bl Conventional technology and problems Generally, communication equipment used for important communication lines is duplicated, so if the current equipment breaks down, it can be switched to the backup equipment, or two equipments can be operated in parallel.) In such cases, controls such as disconnecting the malfunctioning equipment are taken to prevent communication line interruptions.

FIG. 1 shows a conventional example of a switching control circuit for duplexed equipment.

In the figure, device #0 and device #1 mutually monitor the operating status of the other device, and when they wish to switch devices, they request the other station to switch without issuing a switching command signal. Emit only a signal.

For example, if you wish to switch to spare device #1 due to a failure of the current device #0 (excluding power failure) or maintenance, use device #0.
A switching request signal #0-CR is sent from 0 to the standby device #1. Device #1 determines whether to issue a switching command signal #1-CD based on this switching request signal and the obtained operating state of device #0, and gates this switching command signal #1-CD if appropriate. It is sent to flip-flop circuit D-FF via circuit G4. This flip-flop circuit D-F
F is inverted every time a switching command signal is input, and correspondingly, selection signals #O-3 and #1-5 are switched between devices #0 and #0.
1, and switching between the active machine and the standby machine is performed.

However, even if, for example, the switching request signal #1-CR is mistakenly sent from the failed backup device #1 to the active device #0, device #0 knows the status of device #1 and can make the decision on its own. This switching request signal is ignored and device #1 is not switched.

Further, as another switching method, there is a method in which a switching control circuit monitors the status of the active machine and the standby machine and performs switching control.

In the case of the former switching method, for example, the current device #0 is operating normally, but the power supply section of the backup device #1 has become abnormal, so the switching request signal #1-cp is sent from the device #1 by mistake.
When switching command signal #1-CD is sent to device #0 and flip-flop circuit D-FF, this flip-flop knob circuit D-FF switches to device #0 which is operating normally as described above. Since the communication line is switched to device #1 having an abnormal power supply section, the communication line may be disconnected.

In the latter case, a large amount of information is required to determine the switching conditions, making the switching control circuit complex and large-scale.

As mentioned above, with the switching control circuits currently used, there is a possibility that the communication line will be disconnected, but in order to reduce this possibility as close to O as possible, the circuit itself must be complicated and large-scale. There was a problem that the cost of the device increased.

(C) Purpose of the Invention The present invention has been made in view of the above-mentioned problems of the prior art. An object of the present invention is to provide a switching control circuit that prevents malfunctions from switching to a device connected to a device.

(d+ Structure of the Invention The object of the above invention is to detect an abnormality in a device having a redundant configuration having a switching control circuit by using a circuit for detecting an abnormality in the power supply section of the device and an output from the detection circuit. This is achieved by providing a switching control circuit with malfunction prevention, characterized in that a circuit for blocking a switching command signal from a device connected to a power supply section is added to the input side of the switching control circuit.

(81 Examples of inventions FIG. 2 is a block connection diagram of an embodiment of the present invention.

In the figure, #0 and #1 represent device #0 and device #1, respectively, and #0-PD and #1-P[] represent the power abnormality detector of device #0 and the power abnormality detector of device #1, respectively. , D-
FF is a flip-flop circuit, Gj and G3 are each an inhibit circuit, POW is a power supply circuit for the switching control circuit, and AMP-1 to AMP-4 are each an amplifier.
G.

, G7. and G4 each indicate a gate circuit.

Each of these blocks is connected as follows.

Output voltage monitoring terminals 0 and 1 of power supply units (not shown) included in devices #0 and #1 are power abnormality detector #0-PD of device #0 and power abnormality detector #1 of device #1, respectively. #
1-Amplification DAMP-1,AM contained in PD
To the input terminal of P-2 and amplifier MP-3゜8 MP-4
The output terminals of the amplifiers AMP-1 and AMP-2 are connected to the input terminals of the gate circuit Go, and the output terminal of the gate circuit G0 is connected to the input terminal of the gate circuit G2 via the inhibition circuit G1. ■Amplifier AMP-3,
Each output terminal of AMP-4 is connected to the input terminals ■ and ■ of the gate circuit G4, and the output terminal of this gate circuit G is connected to the input terminal ■ of the gate circuit G2 via the inhibition circuit G3, and the output terminal of the gate circuit Gλ is connected to the input terminal ■ of the gate circuit G2. The terminal is a flip-flop circuit D
- Amplifier/IMP -1 and AMP are connected to the CK terminal of the FF.
Another input terminal of -4 is connected to the reference voltage VH6 and VMI.
Further input terminals of amplifiers AMP-2 and AMP-3 are connected to reference voltages VLO and VLI, respectively. The terminals of this flip-flop circuit are connected to device #l via terminal 0, terminal 0 is connected to device #0, and device #0 and device #1 are connected to device #1 through terminal 0.
1 are connected to the input terminals 2 of the inhibition circuit G and G3, respectively.

Further, device #0 and device #1 are connected by a line.

Note that the portion of the present invention is surrounded by a dotted line.

The explanation of the operation of the switching control circuit with malfunction prevention connected in this way overlaps with the explanation of the operation of the conventional example except for the dotted lines, so the overlapping parts will be omitted from the outline and the parts of the present invention will be explained. Explain in detail.

Device #0 and device #1 each monitor the status of the other device. Therefore, as mentioned above, in order to maintain one device or when a failure other than a power supply abnormality occurs, for example, a backup signal is provided for the switching request signal #0-C11 sent from the current device #0 to the backup device #1. According to the switching command signal #1-CD from device #1, the flip-flop circuit D-FF is inverted and selection signals '#os and #1-3 are sent to device #0 and device #I. The current device #0 is switched to the backup device #1.

Also, while the current device #0 is operating normally, the backup device #l encounters a failure (excluding power failure) and erroneously sends the switching request signal #1-C1? to the device #0. Even if the request is sent, since device #0 knows that device #1 is abnormal as described above, the request is ignored and switching to device #1 is not performed.

However, in the event of a power supply abnormality in which the power supply voltage of device #1 gradually drops, for example, device #1 will switch over to switching command signal #1.
There is a skewer that sends two signals to the outside: -CD and switching request signal #1 -CI'l.

At this time, the amplifier AMP in the power supply abnormality detector #1-PD
-3 detects that the power supply voltage of #1 has fallen below the specified voltage VL, and uses the output of this amplifier AMP-3 to set the terminal ■ of the gate circuit to the "1" state.
, the terminal (2) becomes "1", and the switching command signal #1-CD applied to the terminal (2) cannot pass through the inhibition circuit G3. When the power supply voltage becomes higher than the specified voltage VH, the amplifier AMP-'tr detects this, and in the same process as above, the switching command signal #1-CD is activated by the inhibition circuit G.
prevent it from passing through. Therefore, since the flip-flop D-FF remains unchanged, switching from device #0 to device #1 is not performed.

Note that the power supplied to this switching circuit with malfunction prevention (Jt1) is from a power supply p that is separate from the power supply units of devices #0 and #1.

Since it is supplied from W, it is not affected by voltage fluctuations in the device power supply section.

(fl As described in detail, according to the present invention, by adding a power supply abnormality detector and an inhibition circuit to the input side of the conventional switching control circuit, each power supply of device #O or device #1 is If the voltage range exceeds the specified voltage range, the output from the power supply abnormality detector operates the prohibition circuit to prevent the switching command signal from the device connected to the abnormal power supply from being input to the flip-flop circuit. Therefore, the switching of devices connected to the abnormal power supply section is not interrupted, and it is possible to prevent all lines due to a power failure of a communication device with a duplex configuration.

[Brief explanation of the drawing]

FIG. 1 shows a block connection diagram of a conventional switching control circuit, and FIG. 2 shows a block connection diagram of an embodiment of the present invention. In the figure, #0 and #1 represent device #0 and device #1, and #0-
PD and #1-PD are for the power abnormality detector of device #0 and power abnormality detector of device #1, D-FF is the flip-flow knob circuit, G1 and G3 are the inhibit circuit, and POW is for the switching control circuit. Power supply circuit, AMP-1 to AMP-4
indicates an amplifier, and Go, G, and G3 indicate gate circuits, respectively.

Claims (1)

[Claims] In a device with a redundant configuration having a switching control circuit, a circuit for detecting an abnormality in the power supply section of the device and a switching command from the device connected to the abnormal power supply section based on the output from the detection circuit. A switching control circuit with malfunction prevention, characterized in that a circuit for fixing a signal is added to the input side of the switching control circuit.