JPH11345140A - System and method for monitoring duplex systems - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously and normally operate a duplex system monitoring device by detecting the fault of a computer, when the fault occurs on a transmission line. SOLUTION: When fault occurs on the transmission line and a fault occurs at a first computer system, the value of a state signal to the duplex system monitoring device is kept unchanged at L. At this time, since the value of a state signal is not changed for the duplex system monitoring device and only the value of a state change signal is changed, the occurrence of a fault on a DIO cable is decided, the value of a mode switching signal to the first computer system is changed to L, the value of a mode switching signal to a second computer system is changed to H, the first computer system is switched to a standby mode, and the second computer system is switched to a control mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention monitors two computers, one of which operates in a control mode and the other of which operates in a standby mode, with a predetermined monitoring device via a predetermined transmission line, and operates in a control mode. When a failure occurs in a computer, a dual system monitoring system and a dual system monitoring method that change the operation mode of the failed computer to the standby mode and change the operation mode of the computer operating in the standby mode to the control mode It is about.

[0002]

2. Description of the Related Art FIG.
And FIG. 18 is a block diagram showing an example of the configuration of a system to which the dual monitoring system is applied. In FIG. 17, 1 is a first computer of the two systems, 2 is a second computer, and 3 is a dual computer that monitors the operating states of the first computer 1 and the second computer 2. Monitoring device, 4
Is a DI that connects the first computer 1 and the dual monitoring device 3
An O cable 5 is a DIO cable that connects the second computer 2 and the dual monitoring device 3, and a DIO cable 6 that connects the first computer 1 and the second computer 2.

In the first computer 1, 21a is the first computer.
22-1 is a control circuit that sets the operation mode (control mode or standby mode) of the system computer 1 and notifies the dual system monitoring device 3 or the second system computer 2 of the operation state of the first system computer 22-1 And 22-2, a switch unit is connected to the control circuit 21a, one end of a coil unit for controlling ON / OFF of the switch unit is grounded, and the other end is connected via a DIO cable 4 to a relay 42- in the dual system monitoring device 3. 1
1, 42-21 are relays connected to one ends of the switch units, respectively. 23-1 and 23-2 each have a coil unit connected to the control circuit 21a and one end of the switch unit connected to the DI.
One end of the current limiting resistor 43-1 in the dual monitoring device 3 is connected via the O cable 4 and the other end is connected to the relay 43-1 in the dual monitoring device 3 via the DIO cable 4.
1, 43-21 are relays respectively connected to one ends of the coil portions, and 26 is a relay connected to the power supply at one end, and the other end is a relay 42-11 in the dual system monitoring device 3 via the DIO cable 4. 42-21 is a current limiting resistor connected to the other end of the switch section.

[0004] 24-1 and 24-2 have a switch unit connected to the control circuit 21a, one end of the coil unit grounded, and the other end connected via a DIO cable 6 to relays 25-1 and 25-2 in the second computer 2. 25-1 are relays respectively connected to one end of a switch unit, and 25-1 and 25-2.
-2, a coil unit is connected to the control circuit 21a, one end of the switch unit is connected to one end of the current limiting resistor 27, and the other end is connected to the relays 24-1 and 24 in the second computer 2 via the DIO cable 6. -2 is a relay connected to one end of the coil unit, and 27 is a current limiting resistor having one end connected to the power supply and the other end connected to the other ends of the switch units of the relays 25-1 and 25-2. It is.

[0005] In the dual system monitoring device 3, 41a receives operation states from the first system computer 1 and the second system computer 2, and according to the operation states, the first system computer 1 and the second system computer. The control circuit 42-11 requests the switching of the operation mode of the second computer 2 through the DIO cable 4 at one end of the switch unit. Are connected to the current limiting resistor 26 of the first computer 1 via the DIO cable 4, and the coil is connected to the control circuit 41a. Reference numeral 22 denotes one end of the switch unit via the DIO cable 5 and relays 22-1 and 22-2 in the second computer 2.
2-2, and the other end is a DIO cable 5
Is a relay connected to the current limiting resistor 26 of the second computer 2 via a control circuit 41a and a coil unit connected to the control circuit 41a.

In the switches 43-11 and 43-21, the switch section is connected to the control circuit 41a, one end of the coil section is grounded, and the other end is connected to the first computer 1 via the DIO cable 4.
Are connected to one ends of the switch units of the relays 23-1 and 23-2, respectively. The switch units of 43-12 and 43-22 are connected to the control circuit 41a, one end of the coil unit is grounded, The other end is connected via a DIO cable 5 to the relays 23-1 and 23-2 in the second computer 2.
32-1 is a relay connected to one end of the switch unit, and 43-1 has one end connected to the power supply and the other end connected to D.
Current limiting resistors 43-2 are connected to the switches of the relays 23-1 and 23-2 in the first computer 1 via the IO cable 4. One end of the current limiting resistor 43-2 is connected to the power supply, and the other end is a DIO cable. 5 is a current limiting resistor connected to the switches of the relays 23-1 and 23-2 in the second computer 2.

The second computer 2 is connected to the first computer 1
It is configured similarly to.

[0008] Such a dual monitoring system is applied, for example, as shown in FIG. That is, the first computer 1 and the second computer 2 supply an output signal for controlling the peripheral device 10 such as a printer or a modem to the dual output switching device 9 and input the input signal from the peripheral device 10. Various processes are executed based on the signal. The dual system monitoring device 3 notifies the dual system output switching device 9 whether one of the first system computer 1 and the second system computer 2 is in the control mode. , A signal from the computer in the control mode is supplied to the peripheral device 10.

Next, the operation will be described. FIG. 19 is a timing chart showing various signals when a failure occurs in the first computer 1 in the conventional apparatus.
5 is a timing chart showing various signals when, for example, the DIO cable 4 is disconnected when a failure occurs in the first computer 1 in the conventional apparatus.

The control circuit 21a of the computer in the control mode of the first computer 1 and the second computer 2 has a relay 2
3-1 to continuously supply a mode signal having a value of H (High) to the dual system monitoring device 3 via the DIO cables 4 and 5, and the computer in the standby mode uses the relay 23-
1 to continuously supply a mode signal having a value of L (Low).

The control circuit 21a of the first computer 1 and the second computer 2 controls the relay 23-2 to output a state signal having a value L during normal operation and a signal H having a value H when a failure occurs. A certain state signal is continuously supplied to the dual system monitoring device 3 via the DIO cables 4 and 5.

On the other hand, the control circuit 41a of the dual system monitoring device 3
Are relays 42-11, 42-21, 42-12, 42
-22, the mode switching request signal having a value of H when the operation mode is set to the control mode and a value of L when the operation mode is set to the standby mode is set to DIO.
The signals are supplied to the first computer 1 and the second computer 2 via the cables 4 and 5.

Here, as shown in FIG. 19, when a failure occurs in the first computer 1, the value of the status signal from the first computer 1 to the dual monitoring device 3 changes from L to H. Change. When the control circuit 41a of the dual system monitoring device 3 detects that a failure has occurred in the first system computer 1 based on a change in the value of the state signal, first, the value of the state signal from the second system computer 2 becomes L , That is, after confirming that the second computer 2 is normal, the relay 42-11,
42-21, 42-12, and 42-22 to control the first
The value of the mode switching signal to the system computer 1 is changed to L, and the second
The value of the mode switching signal to the system computer 2 is changed to H.

When the second system computer 2 detects that the value of the mode switching signal from the dual system monitoring device 3 has changed to H, it changes the operation mode from the standby mode to the control mode.

In this way, when a failure occurs in the first computer 1, the second computer 2 in the standby mode
Shifts to the control mode. Here, the operation when the failure occurs in the first computer 1 has been described. However, when the failure occurs in the second computer 2 in the control mode, the operation mode of the first computer 1 is changed. Similarly, the mode is changed from the standby mode to the control mode. Further, when the dual system monitoring device 3 fails, the first system computer 1 and the second system computer 2 appropriately transmit and receive necessary information via the DIO cable 6, and the first system computer 1 or the second The system computer 2 continues the normal operation.

[0016]

Since the conventional dual system monitoring system is configured as described above, any one of the first system computer 1, the second system computer 2, and the dual system monitoring device 3 fails. When the error occurs, the system can continue to operate normally, but the DIO cables 4 and 5 between the computer operating in the control mode and the dual system monitoring device 3 may be disconnected. If the connector for connecting the cable is broken, when a failure occurs in the computer, the value of the status signal from the computer is displayed as shown in FIG. Remain the same as in the normal state, the dual system monitoring device 3 cannot detect the failure of the computer, and it is difficult to continuously operate normally as a system. .

The dual system monitoring device 3 and the first system computer 1
In addition to providing the DIO cables 4 and 5 between the second system computer 2 and the second system computer 2, the first system computer 1 and the second system computer 2 provide necessary information when the dual system monitoring device 3 fails. Since the DIO cable 6 is provided for transmission and reception, there is a problem that the laying of the DIO cables 4, 5, and 6 becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and supplies a first signal indicating an operation state of a computer to a monitoring device via a transmission line, and
A second signal indicating whether any of the signals has changed state to the monitoring device, and based on the second signal from the computer operating in the control mode, If the state of any of the first signals supplied via the transmission path has not changed when detecting that any of the states has changed, a failure has occurred in the transmission path to the computer. It is determined that the computer is changed to the standby system, the computer operating in the standby mode is changed to the control system,
A dual system monitoring system and a dual system monitoring method capable of continuously and normally operating as a system even when a failure occurs in a transmission path between a computer operating in a control mode and a monitoring device. The purpose is to:

Further, according to the present invention, a predetermined waveform is superimposed on a first signal representing an operation state of a computer every predetermined period, and a signal generated by superimposition is supplied to a monitoring device via a transmission line. If the predetermined waveform is not detected from a signal supplied from the computer operating in the control mode via the transmission path, it is determined that a failure has occurred in the transmission path to the computer, and the computer is placed in a standby system. And the computer operating in the standby mode is changed to the control system, so that even if a failure occurs in the transmission path between the computer operating in the control mode and the monitoring device, the system continues to operate normally. It is an object of the present invention to obtain a dual system monitoring system and a dual system monitoring method capable of operating in a single system.

Further, according to the present invention, a signal having a cycle corresponding to an operation state of a computer is supplied to a monitoring device via a transmission line.
If the signal supplied from the computer operating in the control mode via the transmission line is DC, it is determined that a failure has occurred in the transmission line between the computer and the computer, and the computer is changed to a standby system, and the standby mode is changed. By changing the computer operating on the control system to the control system, even if a failure occurs in the transmission path between the computer operating in the control mode and the monitoring device, the system can continue to operate normally normally It is an object of the present invention to obtain a simple dual system monitoring system and a dual system monitoring method.

Further, according to the present invention, when the operation state of the computer changes, a predetermined first waveform is superimposed on a signal whose state changes among signals representing the operation state of the computer,
A predetermined second waveform is superimposed on a signal whose state does not change in synchronization with the first waveform, and a signal representing the operation state of the computer is supplied to the monitoring device via a transmission line, and the computer operating in the control mode is When the first waveform or the second waveform is detected from any of the signals supplied through the transmission path and the first waveform or the second waveform is not detected from any of the other signals, It is determined that a failure has occurred in the transmission line between the computer and the computer, the computer is changed to the standby system, the computer operating in the standby mode is changed to the control system, and the computer operating in the control mode is monitored. It is an object of the present invention to provide a dual system monitoring system and a dual system monitoring method capable of continuously operating normally as a system even when a failure occurs in a transmission path between the device and a device.

Further, according to the present invention, every predetermined period,
One computer and the monitoring device, the other computer and the monitoring device, so that one computer and the other computer are electrically connected in order, omitting the transmission line connecting the one computer and the other computer, It is an object of the present invention to provide a dual monitoring system capable of simplifying a transmission line connected to a computer or a monitoring device.

[0023]

A dual system monitoring system according to the present invention supplies a first signal indicating an operation state of a computer to a monitoring device via a transmission line, and further includes a first signal of the first signal. A second signal indicating whether any of the states has changed is supplied to the monitoring device, and based on a second signal from the computer operating in the control mode, the state of any of the first signals is changed. If the state of any of the first signals supplied via the transmission path has not changed when the change is detected, it is determined that a failure has occurred in the transmission path to the computer, and The operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode.

The dual system monitoring system according to the present invention superimposes a predetermined waveform at predetermined intervals on a first signal indicating an operation state of a computer, and transmits a signal generated by superimposition via a transmission line. If a predetermined waveform is not detected from a signal supplied via a transmission path from a computer operating in the control mode, it is determined that a failure has occurred in the transmission path between the computer and the computer. The operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode.

In the dual system monitoring system according to the present invention, a signal having a cycle corresponding to the operation state of the computer is supplied to the monitoring device via the transmission line, and supplied from the computer operating in the control mode via the transmission line. If the signal is DC, it is determined that a failure has occurred in the transmission path to the computer, the operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is set to the control mode. To change.

A dual system monitoring system according to the present invention, when an operating state of a computer changes, superimposes a predetermined first waveform on a signal whose state changes among signals indicating the operating state of the computer, After superimposing a predetermined second waveform on a signal whose state does not change in synchronization with the first waveform, a signal representing an operation state of the computer is supplied to the monitoring device via a transmission line, and the computer operates in the control mode. When the first waveform or the second waveform is detected from any of the signals supplied through the transmission path from the other, and the first waveform or the second waveform is not detected from any of the other signals Then, it is determined that a failure has occurred in the transmission path to the computer, the operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode.

A dual system monitoring system according to the present invention provides a connection for electrically connecting one computer and a monitoring device, the other computer and a monitoring device, and one computer and the other computer in order at predetermined intervals. It has a switching unit.

In the dual system monitoring system according to the present invention, when the monitoring device fails, only one computer and the other computer are electrically connected.

According to the dual system monitoring method of the present invention, a first signal indicating an operation state of a computer is supplied to a monitoring device via a transmission line, and a state of any one of the first signals changes. A second signal indicating whether the operation has been performed is supplied to the monitoring device, and it is detected that a state of any of the first signals has changed based on the second signal from the computer operating in the control mode. When the state of any of the first signals supplied via the transmission path has not changed, it is determined that a failure has occurred in the transmission path to the computer, and the operation mode of the computer is awaited. Mode, and the operation mode of the computer operating in the standby mode is changed to the control mode.

According to the dual system monitoring method of the present invention, a predetermined waveform is superimposed on a first signal representing an operation state of a computer every predetermined period, and a signal generated by superimposition is transmitted via a transmission line. If a predetermined waveform is not detected from a signal supplied via a transmission path from a computer operating in the control mode, it is determined that a failure has occurred in the transmission path between the computer and the computer. The operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode.

In the dual system monitoring method according to the present invention, a signal having a cycle corresponding to the operation state of the computer is supplied to the monitoring device via the transmission line, and supplied from the computer operating in the control mode via the transmission line. If the signal is DC, it is determined that a failure has occurred in the transmission path to the computer, the operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is set to the control mode. To change.

According to the dual system monitoring method of the present invention, when the operating state of a computer changes, a predetermined first waveform is superimposed on a signal whose state changes among signals representing the operating state of the computer. After a predetermined second waveform is superimposed on a signal whose state does not change in synchronization with the first waveform, a signal indicating an operation state of the computer is supplied to the monitoring device via a transmission line, and the computer operates in the control mode. When the first waveform or the second waveform is detected from any of the signals supplied from the computer via the transmission path, the first waveform or the second waveform is not detected from any of the other signals. In this case, it is determined that a failure has occurred in the transmission path to the computer, the operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of a dual monitoring system according to the first embodiment of the present invention, and FIG. 2 is a state change signal provided in each computer of the dual monitoring system according to the first embodiment. FIG. 3 is a circuit diagram illustrating a configuration example of a generation unit 61. In FIG. 1, 1 is a first computer (computer) of the two systems, 2 is a second computer (computer), and 3 is a first computer 1 and a second computer 2
, A dual system monitoring device (monitoring device) for monitoring the operation status of the first computer 1, a DIO cable connecting the first computer 1 and the dual system monitoring device 3, and a reference numeral 5 for the second computer 2 Reference numeral 6 denotes a DIO cable for connecting the heavy system monitoring device 3, and 6 denotes a DIO cable for connecting the first system computer 1 and the second system computer 2. Note that the DIO cable is also called a DIDO cable, and DIDO is an abbreviation for digital-in / digital-out.

In the first computer 1, reference numeral 21 denotes an operation mode (control mode or standby mode) of the first computer 1.
And a control circuit that notifies the dual system monitoring device 3 or the second system computer 2 of the operating state of the first system computer 1. One end of a coil unit that is connected and controls on / off of a switch unit is grounded, and the other end is connected via a DIO cable 4 to relays 42-11, 4 in the dual system monitoring device 3.
Reference numerals 22-1 and 23-2 denote relays connected to one end of a switch unit, respectively. A coil unit is connected to the control circuit 21 and one end of the switch unit is a duplex system via the DIO cable 4. Current limiting resistor 4 in monitoring device 3
3-1 is connected to one end, and the other end is connected via a DIO cable 4 to the relays 43-11 and 43 in the dual system monitoring device 3.
Reference numeral 26 denotes a relay connected to one end of the coil unit 21. One end of the relay 42 is connected to the power supply, and the other end is connected to the relay 42 of the dual monitoring device 3 via the DIO cable 4.
-11 and 42-21 are current limiting resistors connected to the other ends of the switch units.

Reference numeral 61 is provided in the control circuit 21 and controls the relay 51 so that the relays 23-1, 23-2 and DI
Supplied to the dual system monitoring device 3 via the O cable 4;
When any one of the mode signal (first signal) representing the operation mode and the state signal (first signal) representing whether or not a failure has occurred changes, the state change signal (predetermined waveform) has a predetermined waveform. A state change signal generating unit that generates the second signal) and supplies the signal to the duplex monitoring device 3 via the DIO cable 4.

In FIG. 2, reference numeral 81 denotes a relay 23-1,
23-2, a control signal, that is, a state signal and a state signal, are supplied, and the exclusive OR of the value of the state signal and the value of the state signal is calculated.
2 is an EXOR circuit that outputs to the D input terminal of
Is supplied with a clock signal appropriately generated by the control circuit 21, holds the value of the D input terminal at the timing of the rising edge of the clock signal until the next rising timing, and holds the value via the Q output terminal. 8
3 is a D flip-flop that supplies a D input terminal and a comparator 84. The D flip-flop 83 is supplied with a clock signal appropriately generated by the control circuit 21, and changes the value of the D input terminal at the rising timing of the clock signal to the next value. A D flip-flop which holds the signal until the rising timing and supplies the value to a comparator 84 via a Q output terminal.
Compares the value of the signal from the D flip-flop 82 with the value of the signal from the D flip-flop 83, and when they are the same, the value is L, and when they are different from each other, the value is H Is a signal for controlling the relay 51,
That is, it is a comparator that outputs as a state change signal.

Returning to FIG. 1, reference numeral 51 denotes a current limiting resistor 43 in the dual system monitoring device 3 in which the coil is connected to the state change signal generator 61 of the control circuit 21 and one end of the switch is connected via the DIO cable 4. -1 is connected to one end of the switch unit, and the other end of the switch unit is connected to the coil unit of the relay 71-1 in the dual system monitoring device 3 via the DIO cable 4.

In 24-1 and 24-2, a switch section is connected to the control circuit 21, one end of the coil section is grounded,
The other end is a relay connected to one end of the switch unit of each of the relays 25-1 and 25-2 in the second computer 2 via the DIO cable 6, and 25-1 and 25-2.
Has a coil section connected to the control circuit 21, one end of the switch section connected to one end of the current limiting resistor 27, and the other end connected to DI.
The relay 2 in the second computer 2 via the O cable 6
Relays connected to one ends of the coil units of 4-1 and 24-2, respectively, have one end connected to the power supply and the other end connected to the other ends of the switch units of the relays 25-1 and 25-2. Current limiting resistor.

In the dual system monitoring device 3, reference numeral 41 denotes the first
A control circuit that receives operation states from the system computer 1 and the second system computer 2, and requests the first system computer 1 and the second system computer 2 to switch the operation mode in accordance with the operation states; 42-11 and 42-21, one end of the switch unit is connected to the coil units of the relays 22-1 and 22-2 in the first computer 1 via the DIO cable 4, and the other end is connected via the DIO cable 4. First computer 1
Are connected to the current limiting resistor 26, and the coil section is connected to the control circuit 41. The relays 42-12 and 42-22 are connected to the second computer 2 at one end of the switch section via the DIO cable 5. 22-1, 22
2 is connected to the current limiting resistor 26 of the second computer 2 via the DIO cable 5, and the coil is connected to the control circuit 41.

The switches 43-11 and 43-21 have a switch connected to the control circuit 41, one end of the coil is grounded, and the other end is connected via the DIO cable 4 to the relays 23-1 and 23-1 in the first computer 1. 23-2 are relays respectively connected to one end of the switch unit;
3-22, the switch unit is connected to the control circuit 41, one end of the coil unit is grounded, and the other end is connected via the DIO cable 5 to the relays 23-1 and 23-2 in the second computer 2.
43-1 is a relay connected to one end of the switch unit, and 43-1 has one end connected to the power supply and the other end connected to the DIO.
Relay 23 in the first computer 1 via the cable 4
43-2, a current limiting resistor connected to the switch unit, 43-2 has one end connected to the power supply and the other end connected to D
This is a current limiting resistor connected to the switches of the relays 23-1 and 23-2 in the second computer 2 via the IO cable 5.

71-1 has one end of the coil portion grounded,
The other end is connected to the switch of the relay 51 of the first computer 1 via the DIO cable 4, and the switch is connected to the control circuit 41. Reference numeral 71-2 denotes one end of the coil which is grounded. The other end is connected to the switch of the relay 51 in the second computer 2 via the DIO cable 5, and the switch is connected to the control circuit 41.

The second computer 2 is configured in the same manner as the first computer 1, and a description thereof will be omitted.

Next, the operation will be described. FIG. 3 is a timing chart showing various signals when a failure occurs in the first computer 1 in the first embodiment.
6 is a timing chart showing various signals when a failure occurs in the first computer 1 according to the first embodiment, for example, when the DIO cable 4 is disconnected.

The control circuit 21 of the computer in the control mode of the first computer 1 and the second computer 2 includes a relay 23
-1 to continuously supply the mode signal having the value H to the dual system monitoring device 3 via the DIO cables 4 and 5, and the computer in the standby mode controls the relay 23-1 to control the relay 23-1. , And the mode signal whose value is L is continuously supplied.

The control circuit 21 of the first computer 1 and the second computer 2 controls the relay 23-2 to output a state signal having a value L during normal operation and a signal H having a value H when a failure occurs. A certain state signal is continuously supplied to the dual system monitoring device 3 via the DIO cables 4 and 5.

Further, the control circuit 21 of the first computer 1 and the second computer 2 controls the relay 51 by the state change signal generator 61 to change both the mode signal value and the state signal value. If not, the value is L,
When there is a change in either the value of the mode signal or the value of the state signal, a state change signal whose value is H for a predetermined time is supplied to the dual system monitoring device 3.

On the other hand, the control circuit 41 of the dual system monitoring device 3
Are relays 42-11, 42-21, 42-12, 42
-22, the mode switching request signal having a value of H when the operation mode is set to the control mode and a value of L when the operation mode is set to the standby mode is set to DIO.
The signals are supplied to the first computer 1 and the second computer 2 via the cables 4 and 5.

Here, as shown in FIG. 3, when a failure occurs in the first computer 1, the value of the status signal from the first computer 1 to the dual monitoring device 3 changes from L to H. At the same time, the value of the state change signal becomes H for a predetermined time.
When the control circuit 41 of the dual system monitoring device 3 detects that a failure has occurred in the first system computer 1 from the change in the value of the state signal and the state change signal, first, the state signal from the second system computer 2 is detected. After confirming that the value of L is L, that is, confirming that the second computer 2 is normal, the relays 42-11, 42-21, 42-12, and 42-22 are controlled to The value of the mode switching signal to the first computer 1 is changed to L, and the value of the mode switching signal to the second computer 2 is changed to H.

When the second system computer 2 detects that the value of the mode switching signal from the dual system monitoring device 3 has changed to H, it changes the operation mode from the standby mode to the control mode.

As described above, when the transmission path such as the DIO cable 4 between the first computer 1 and the dual system monitoring device 3 is normal, the dual system monitoring device 3 The first computer 1 based on the change in the value of the state signal from the computer 1
To detect a failure.

On the other hand, the first computer 1 and the dual system monitor 3
When a failure occurs in the first computer 1 in the case where a failure occurs in the transmission path between the first computer 1 and the dual system monitoring device 3 as shown in FIG. The value remains at L. At this time, the dual system monitoring device 3
Determines that a failure has occurred in the DIO cable 4 (that is, the signal line through which the state signal is transmitted in the DIO cable 4) because the value of the state signal does not change and only the value of the state change signal changes. The value of the mode switching signal to the first computer 1 is changed to L, the value of the mode switching signal to the second computer 2 is changed to H, the first computer 1 is put into the standby mode, and the second The computer 2 is shifted to the control mode. Thereafter, the dual system monitoring device 3 determines whether the mode signal and the state change signal from the second system computer 2 have changed in value.
Confirm that the operation mode has been changed successfully.

Here, the case where the first computer 1 in the control mode has failed has been described. However, the same operation is performed when the second computer 2 in the control mode has failed. The first computer 1 shifts from the standby mode to the control mode.

As described above, according to the first embodiment, the mode signal and the status signal as the first signals indicating the operation status of each of the computers 1 and 2 are monitored via the DIO cables 4 and 5 for the dual system monitoring. A status change signal from the computer operating in the control mode is supplied to the dual system monitoring device 3 while supplying the status change signal indicating whether or not any one of the first signals has changed in status. When detecting that the state of any of the first signals has changed based on the signal, if none of the states of the first signal supplied via the transmission line has changed, the computer It is determined that a failure has occurred in the transmission path between the computer and the standby system, and the computer is changed to the standby system, and the computer operating in the standby mode is changed to the control system. A failure has occurred in the transmission path between Even if the effect is obtained that it is possible to operate normally continue as a system.

Embodiment 2 FIG. 5 is a block diagram showing a configuration of the dual monitoring system according to the second embodiment of the present invention. In the figure, reference numeral 91 denotes a predetermined period T3,
This is a rectangular wave superimposing unit that superimposes a rectangular wave whose cycle is T1 for a predetermined period T2 on the mode signal and the state signal, respectively. The other components are the same as those of the first embodiment, and thus the description thereof will be omitted. In the dual system monitoring system according to the second embodiment, the relay 51, the state change signal generator 61, and the relays 71-1 and 71-2 in the first embodiment are not provided.

Next, the operation will be described. FIG. 6 is a timing chart showing various signals when a failure occurs in the first computer 1 in the second embodiment.
9 is a timing chart showing various signals when a failure occurs in the first computer 1 according to the second embodiment, for example, when the DIO cable 4 is disconnected.

The control circuit 21 of the computer in the control mode of the first computer 1 and the second computer 2 includes a relay 23
-1 to continuously supply the mode signal having the value H to the dual system monitoring device 3 via the DIO cables 4 and 5, and the computer in the standby mode controls the relay 23-1 to control the relay 23-1. , And the mode signal whose value is L is continuously supplied. At this time, each computer superimposes a rectangular wave having a cycle of T1 on the mode signal by the rectangular wave superimposing means 91 for each predetermined period T3 for the predetermined period T2.

The control circuit 21 of the first computer 1 and the second computer 2 controls the relay 23-2 to output a state signal having a value L during a normal operation and a signal H having a value H when a failure occurs. A certain state signal is continuously supplied to the dual system monitoring device 3 via the DIO cables 4 and 5. At this time, each computer uses the rectangular wave superimposing means 91 for every predetermined period T3.
A rectangular wave whose cycle is T1 is superimposed on the state signal for a predetermined period T2.

On the other hand, the control circuit 41 of the dual system monitoring device 3
Are relays 42-11, 42-21, 42-12, 42
-22, the mode switching request signal having a value of H when the operation mode is set to the control mode and a value of L when the operation mode is set to the standby mode is set to DIO.
It is continuously supplied to the first computer 1 and the second computer 2 via the cables 4 and 5. At this time, the dual monitoring device 3
Is calculated by the rectangular wave superimposing means 91 every predetermined period T3.
A rectangular wave whose cycle is T1 is superimposed on the mode switching request signal for a predetermined period T2.

Then, the control circuit 41 detects the rectangular wave superimposed every predetermined period T3, thereby detecting the DIO.
It is confirmed that the transmission path between the first computer 1 such as the cable 4 and the dual system monitoring device 3 is normal. Here, as shown in FIG. 6, when a failure occurs in the first system computer 1, the value of the state signal from the first system computer 1 to the dual system monitoring device 3 changes from L to H. When the control circuit 41 of the dual-system monitoring device 3 detects that a failure has occurred in the first computer 1 based on a change in the value of the status signal, first, the value of the status signal from the second computer 2 becomes L. After confirming that the relays 42-11, 42-21, 42-12, and 42
By controlling −22, the value of the mode switching signal to the first computer 1 is changed to L, and the value of the mode switching signal to the second computer 2 is changed to H.

When the second system computer 2 detects that the value of the mode switching signal from the dual system monitoring device 3 has changed to H, it changes the operation mode from the standby mode to the control mode.

As described above, when the transmission path between the first computer 1 such as the DIO cable 4 and the dual system monitoring device 3 is normal, the dual system monitoring device 3 The first computer 1 based on the change in the value of the state signal from the computer 1
To detect a failure.

On the other hand, the first computer 1 and the dual system monitoring device 3
As shown in FIG. 7, when a failure occurs in the transmission line between the first computer 1 and the first computer 1, a failure occurs in the transmission path between the first computer 1 and the dual system monitoring device 3. The value remains at L. At this time, the dual system monitoring device 3
Determines that a failure has occurred in the DIO cable 4 and determines the value of the mode switching signal to the first system computer 1 to be L because the rectangular wave superimposed on the state signal cannot be detected.
And the value of the mode switching signal to the second computer 2 is set to H
The first computer 1 is shifted to the standby mode, and the second computer 2 is shifted to the control mode. After that, the dual system monitoring device 3 confirms that the operation mode of the second system computer 2 has been normally changed from the change in the values of the mode signal and the state change signal from the second system computer 2.

Here, the case where the first computer 1 in the control mode has failed has been described, but the same operation is performed when the second computer 2 in the control mode has failed. The first computer 1 shifts from the standby mode to the control mode.

As described above, according to the second embodiment, for every predetermined period T3, the cycle is T for the predetermined period T2.
Since the rectangular wave of 1 is superimposed on each signal and a failure of the transmission path can be detected depending on whether or not the rectangular wave is detected, the signal line in which the failure has occurred is specified. And DIO compared to the first embodiment.
The effect that the signal lines of the cables 4 and 5 can be reduced one by one is obtained.

Embodiment 3 In the dual system monitoring system according to the third embodiment of the present invention, when the operation mode is the control mode, the period of the first computer 1 and the second system computer 2 is T5, and the operation mode is the standby mode. , A rectangular wave having a cycle of T4 is supplied as a mode signal to the dual system monitoring device 3 via the DIO cables 4 and 5, respectively. If the operation is normal, the cycle is T4 and a failure occurs. Is generated, a rectangular wave having a cycle of T5 is supplied to the duplex monitoring device 3 as a state signal.

When the operation mode is set to the control mode, the cycle is T5. When the operation mode is set to the standby mode, the cycle is T4.
Is used as the mode switching request signal via the DIO cables 4 and 5 to the first computer 1 and the second computer 2
To supply.

The other structure is the same as that of the second embodiment, and the description is omitted. In the dual system monitoring system according to the third embodiment,
The rectangular wave superimposing means 91 according to the second embodiment is not provided.

Next, the operation will be described. FIG. 8 is a timing chart showing various signals when a failure occurs in the first computer 1 in the third embodiment.
13 is a timing chart showing various signals when a failure occurs in the first computer 1 in the third embodiment, for example, when the DIO cable 4 is disconnected.

The control circuit 21 of the computer in the control mode of the first computer 1 and the second computer 2 has a relay 23
-1 to control the dual system monitoring device 3 via the DIO cables 4 and 5 with a square wave having a cycle of T5 as a mode signal.
And the computer in the standby mode controls the relay 23-1 to supply a rectangular wave having a cycle of T4 as a mode signal.

Further, the control circuit 21 of the first computer 1 and the second computer 2 controls the relay 23-2, and in a normal operation, a rectangular wave whose cycle is T4 is used as a state signal.
When a failure occurs, a rectangular wave having a cycle of T5 is supplied as a state signal to the dual system monitoring device 3 via the DIO cables 4 and 5.

On the other hand, the control circuit 41 of the dual system monitoring device 3
Are relays 42-11, 42-21, 42-12, 42
-22, the period is T5 when the operation mode is set to the control mode, and when the operation mode is set to the standby mode, a rectangular wave having the period T4 is set as a mode switching request signal via the DIO cables 4 and 5. To the first computer 1 and the second computer 2.

Here, as shown in FIG. 8, when a failure occurs in the first computer 1, the cycle of the state signal from the first computer 1 to the dual monitoring device 3 changes from T4 to T5. Change. When the control circuit 41 of the dual-system monitoring device 3 detects that a failure has occurred in the first computer 1 based on a change in the cycle of the status signal, first, the cycle of the status signal from the second computer 2 is set to T4. After confirming that the relay 42-1
1,42-21,42-12,42-22,
The period of the mode switching signal to the first computer 1 is changed to T4, and the period of the mode switching signal to the second computer 2 is changed to T5.

When the second system computer 2 detects that the cycle of the mode switching signal from the dual system monitoring device 3 has changed to T5, it changes the operation mode from the standby mode to the control mode.

In this way, when the transmission path between the first computer 1 such as the DIO cable 4 and the dual system monitoring device 3 is normal, the dual system monitoring device 3 A failure of the first computer 1 is detected based on a change in the period of the state signal from the computer 1.

On the other hand, the first computer 1 and the dual system monitoring device 3
As shown in FIG. 9, when a failure occurs in the transmission path between the first computer 1 and the first computer 1, a failure occurs in the transmission path between the first computer 1 and the dual system monitoring device 3. The value remains at L continuously. At this time, since the status signal is DC, the dual system monitoring device 3 determines that a failure has occurred in the DIO cable 4 and changes the cycle of the mode switching signal to the first system computer 1 to T4. The period of the mode switching signal to the second computer 2 is changed to T5, and the first computer 1 is shifted to the standby mode and the second computer 2 is shifted to the control mode. After that, the dual system monitoring device 3 confirms that the operation mode of the second system computer 2 has been changed normally from the change in the cycle of the mode signal from the second system computer 2.

Here, the case where the first computer 1 in the control mode has failed has been described. However, the same operation is performed when the second computer 2 in the control mode has failed. The first computer 1 shifts from the standby mode to the control mode.

As described above, according to the third embodiment, the computer in the control mode outputs a rectangular wave having a cycle of T5.
The computer in the standby mode supplies a rectangular wave having a cycle of T4 as a mode signal to the dual system monitoring device 3, and each of the computers 1 and 2 outputs a rectangular wave having a cycle of T4 during normal operation and a cycle when a failure occurs. Is supplied as a status signal to the duplex system monitoring device 3 to detect a failure in the transmission path based on whether or not the signal is DC. And the failure can be detected immediately after the occurrence of a failure in the transmission path, and the operation mode can be switched quickly.

Embodiment 4 In the dual monitoring system according to the fourth embodiment of the present invention, when the operation mode or the state of the computer changes, the first system computer 1 and the second system computer 2 respond to the change in the operation mode or the state of the computer. Alternatively, the value of the state signal is changed in the same manner as in the second embodiment,
At this time, of the mode signal or the state signal, a predetermined first waveform (for example, one shown in FIG. 10B) is superimposed on a signal whose value changes, and a predetermined second waveform is superimposed on a signal whose value does not change. After superimposing the waveform (for example, the one shown in FIG. 10C),
A mode signal or a status signal is supplied to the dual monitoring device 3 via the DIO cables 4 and 5, respectively. Other configurations are the same as those of the second embodiment.
The description is omitted. However, in the dual monitoring system according to the fourth embodiment, the rectangular wave superimposing means 91 according to the second embodiment is not particularly provided.

Next, the operation will be described. FIG. 10 is a timing chart showing various signals when a failure occurs in the first computer 1 in the fourth embodiment.
9 is a timing chart showing various signals when a failure occurs in the first computer 1 in the fourth embodiment, for example, when the DIO cable 4 is disconnected.

The control circuit 21 of the computer in the control mode of the first computer 1 and the second computer 2 has a relay 23
-1 to continuously supply the mode signal having the value H to the dual system monitoring device 3 via the DIO cables 4 and 5, and the computer in the standby mode controls the relay 23-1 to control the relay 23-1. , And the mode signal whose value is L is continuously supplied.

The control circuit 21 of the first computer 1 and the second computer 2 controls the relay 23-2 to output a state signal having a value L during normal operation and a signal H having a value H when a failure occurs. A certain state signal is continuously supplied to the dual system monitoring device 3 via the DIO cables 4 and 5.

On the other hand, the control circuit 41 of the dual system monitoring device 3
Are relays 42-11, 42-21, 42-12, 42
-22, the mode switching request signal having a value of H when the operation mode is set to the control mode and a value of L when the operation mode is set to the standby mode is set to DIO.
It is continuously supplied to the first computer 1 and the second computer 2 via the cables 4 and 5.

Here, as shown in FIG.
When a failure occurs in the first computer 1, the first computer 1
, The value of the status signal to the dual system monitoring device 3 changes from L to H. At this time, the waveform shown in FIG. 10B is superimposed on the state signal from the first computer 1 and synchronized with the state signal shown in FIG.
The waveform indicated by 0 (c) is superimposed on the mode signal from the first computer 1.

When the control circuit 41 of the dual system monitoring device 3 detects that a failure has occurred in the first system computer 1 based on the change in the value of the state signal, first, the control circuit 41 transmits the state signal from the second system computer 2. After confirming that the value is L, the relay 42-1
1,42-21,42-12,42-22,
Change the value of the mode switching signal to the first computer 1 to L,
The value of the mode switching signal to the second computer 2 is changed to H.

When the second system computer 2 detects that the value of the mode switching signal from the dual system monitoring device 3 has changed to H, it changes the operation mode from the standby mode to the control mode.

In this way, when the transmission path between the first computer 1 such as the DIO cable 4 and the dual system monitoring device 3 is normal, the dual system monitoring device 3 A failure of the first computer 1 is detected based on a change in the state signal from the computer 1.

On the other hand, the first system computer 1 and the dual system monitoring device 3
When a failure occurs in the first computer 1 in the case where a failure has occurred in the transmission path between the first computer 1 and the dual system monitoring device 3 as shown in FIG. The value remains at L. At this time, the dual system monitoring device 3
10 (b) or 10 (c) is added to the state signal from the first computer 1 although the waveform shown in FIG. 10 (c) is superimposed on the mode signal from the first computer 1. ) Is not superimposed, it is determined that a failure has occurred in the DIO cable 4, the value of the mode switching signal to the first computer 1 is changed to L, and the mode is switched to the second computer 2. The value of the signal is changed to H, the first computer 1 is shifted to the standby mode, and the second computer 2 is shifted to the control mode. After that, the dual system monitoring device 3 confirms that the operation mode of the second system computer 2 has been normally changed from the change in the values of the mode signal and the state change signal from the second system computer 2.

Here, the case where the first computer 1 in the control mode has failed has been described. However, the same operation is performed when the second computer 2 in the control mode has failed. The first computer 1 shifts from the standby mode to the control mode.

As described above, according to the fourth embodiment, when there is a change in the operation mode or the state of the computer, the value of the mode signal or the state signal is correspondingly changed in the same manner as in the second embodiment. At this time, of the mode signal or the state signal, a predetermined first waveform is superimposed on a signal whose value changes, and a predetermined second waveform is superimposed on a signal whose value does not change. A mode signal or a state signal is supplied to the dual system monitoring device 3 so that a failure in the transmission path is detected based on whether the first waveform and the second waveform are detected together. Therefore, the same effect as that of the second embodiment can be obtained, and the number of times of switching the value of each signal is reduced, so that the life of the relay can be extended.

Embodiment 5 FIG. 12 is a block diagram illustrating a configuration of a dual monitoring system according to a fifth embodiment of the present invention. FIG. 13 is a block diagram illustrating a configuration example of a connection switching unit in FIG. In FIG. 12, reference numeral 1 denotes a first computer, 2 denotes a second computer, 3 denotes a dual system monitoring device, and 4 and 5 denote the dual system monitoring device 3 and the first computer 1 and the second computer. DI for connecting to the 2nd computer 2
O cable.

In the first computer 1 and the second computer 2, 101 is provided between the DIO cable 4 and the control circuit 21, and the relays 22-1, 22-2, 23
-1,23-2 or relays 22-1,22-2,
This is an input / output unit composed of 23-1 and 23-2 and a relay 51.

In the dual system monitoring device 3, 112 is D
The IO cables 4 and 5 are connected to the input / output unit 111, and the input / output unit 111 and the input / output unit 101 of the first computer 1 are connected to each other.
The input / output unit 111 and the input / output unit 101 of the second computer 2 are connected to each other by the input / output unit 101 of the first computer 1 and the second computer 2.
Is a connection switching unit for electrically connecting the input / output unit 101 of the relay circuit in order and repeatedly for a predetermined time, and 111 is provided between the control circuit 41 and the connection switching unit 112, and the relay 43-11 described above is provided. , 43-21 or relay 43-1
1, 43-21 and an input / output unit configured by a relay 71-1.

In the connection switching unit 112 shown in FIG.
Reference numeral 1 denotes a control signal output unit that controls the conduction state of the switches 122-1, 122-2, and 122-3.
Is a switch whose one end is connected to the DIO cable 4 and whose other end is connected to the switches 122-2 and 122-3, and which is turned on / off in response to a control signal from the control signal output unit 121. Is a switch that is connected to the DIO cable 5, the other end is connected to the switches 122-1, 122-3, and is turned on / off in response to a control signal from the control signal output unit 121. Section 111, and the other end is connected to switches 122-1, 12
The switch 2-2 is turned on and off in response to a control signal from the control signal output unit 121.

Next, the operation will be described. FIG. 14 is a timing chart illustrating control signals supplied from the control signal output unit 121 of the connection switching unit 112 to the switches 122-1 to 122-3 in the dual system monitoring device 3.

The connection switching unit 11 in the dual system monitoring device 3
The second control signal output unit 121 supplies the control signals shown in FIG. 14 to the switches 122-1 to 122-3, respectively.
The switches 122-1 to 122-3 turn on when the value of the supplied control signal is H, and turn off when the value of the control signal is L. Therefore, in the period T12, the DIO cable 4 and the DIO cable 5 are electrically connected, and the period T12
At 13, the input / output unit 111 of the dual monitoring apparatus 3 and the DIO cable 5 are electrically connected. During the period T <b> 14, the input / output unit 111 of the dual monitoring apparatus 3 and the DIO cable 5 are connected.
The cable 4 is electrically connected.

As described above, in the period T14, the transmission and reception of the mode signal, the status signal, and the mode switching request signal between the dual system monitoring device 3 and the first system computer 1 via the DIO cable 4 are executed. In the period T13, the transmission of the mode signal, the status signal, and the mode switching request signal between the dual system monitoring device 3 and the second system computer 2 via the DIO cable 5 is executed. The exchange of information between the first computer 1 and the second computer 2 via the DIO cable 4 and the DIO cable 5 is appropriately performed. The mode signal, status signal,
Any of the above-described first to fourth embodiments may be used as the mode switching request signal, the state change signal, and the like.

As described above, according to the fifth embodiment, the input / output unit 111 of the dual system monitoring device 3 and the input / output unit 101 of the first computer 1 are connected to the input / output unit of the dual system monitoring device 3. The output unit 111 and the input / output unit 101 of the second computer 2 are electrically connected to each other for a predetermined time by repeating the input / output unit 101 of the first computer 1 and the input / output unit 101 of the second computer 2 in order. Is connected, the cable for directly connecting the first computer 1 and the second computer 2 can be omitted, and the effect of simplifying the transmission path connecting the devices can be obtained. can get.

Embodiment 6 FIG. The dual monitoring system according to the sixth embodiment of the present invention is the same as that according to the fifth embodiment except that the connection switching unit 112 is changed. Therefore, only the connection switching unit 112 will be described. FIG. 15 shows a connection switching unit 1 in the dual system monitoring system according to the sixth embodiment.
FIG. 12 is a block diagram showing a configuration of a twelfth embodiment.

Reference numeral 123 is provided between the control signal output unit 121 and the switches 122-1 to 122-3, and based on a failure signal for notifying a failure in the dual system monitoring device 3,
When a failure occurs, the switch 122-3 is turned off, and the switch 12-3 is turned off.
A connection setting unit for forcibly controlling 2-1 and 122-2 to turn on. In the connection setting unit 123, the control signal 131 is input from the control signal output unit 121 to the switch 122-1, and the failure signal is inverted and input, and the logical sum of the control signal value and the inverted value of the failure signal is input. Is an OR circuit that supplies the operation result to the switch 122-1 as a control signal. The control circuit 132 receives the control signal from the control signal output unit 121 to the switch 122-2 and inverts the failure signal. An OR circuit that calculates the logical sum of the input control signal value and the inverted value of the fault signal, and supplies the calculated result to the switch 122-2 as a control signal;
133 is a signal from the control signal output unit 121 to the switch 122-
3, a fault signal is input, a logical product of the control signal value and the fault signal value is calculated, and the calculation result is used as a control signal as a switch 122-3.
And an AND circuit for supplying the AND circuit. The control signal output unit 1
21 and the switches 122-1 to 122-3 are the same as those according to the fifth embodiment, and a description thereof will be omitted.

Next, the operation will be described. FIG. 16 shows the connection switching unit 11 when a failure occurs in the dual system monitoring device 3.
6 is a timing chart showing control signals supplied to the second switches 122-1 to 122-3.

As shown in FIG. 16, when no failure has occurred in the redundant system monitoring device 3, the value of the failure signal is H, and the signal from the control signal output unit 121 is
3 to the switches 122-1 to 122-3 as they are.

On the other hand, when a failure occurs in the dual system monitoring device 3, the value of the failure signal becomes L and the control signal output unit 1
Connection setting unit 123 regardless of the value of the control signal from
The value of the control signal supplied from the switch to the switch 122-1 is H
The value of the control signal supplied from the connection setting unit 123 to the switch 122-2 becomes H, and the value of the control signal supplied from the connection setting unit 123 to the switch 122-3 becomes L. Therefore, when a failure occurs in the dual monitoring device 3, the DIO cable 4 and the DIO cable 5 are electrically connected. The other operations are the same as those of the fifth embodiment, and the description is omitted.

As described above, according to the sixth embodiment, the same effects as those of the fifth embodiment can be obtained, and when a failure occurs in the dual system monitoring device 3, the first system can be quickly and reliably performed. The effect that the system computer 1 and the second system computer 2 can be electrically connected is obtained.

[0104]

As described above, according to the present invention, the first signal indicating the operation state of the computer is supplied to the monitoring device via the transmission line, and any one of the states of the first signal is supplied. A second signal indicating whether or not the first signal has changed based on a second signal from the computer operating in the control mode. If the state of any of the first signals supplied via the transmission path has not changed at the time of detection, it is determined that a failure has occurred in the transmission path to the computer, and the operation mode of the computer is determined. Is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode, so that when a failure occurs in the transmission path between the computer operating in the control mode and the monitoring device, Also continue to be positive There is an effect that it is possible to operate.

According to the present invention, a predetermined waveform is superimposed on the first signal indicating the operation state of the computer every predetermined period, and the superimposed signal is supplied to the monitoring device via the transmission line. If a predetermined waveform is not detected from a signal supplied from a computer operating in the control mode via a transmission line, it is determined that a failure has occurred in the transmission line between the computer and the computer. Is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode. Therefore, there is an effect that a signal line in which a failure has occurred can be specified.

According to the present invention, a signal having a cycle corresponding to the operation state of the computer is supplied to the monitoring device via the transmission line, and the signal supplied from the computer operating in the control mode via the transmission line is DC. In some cases, it is determined that a failure has occurred in the transmission path to the computer, the operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode. Therefore, the failure can be detected immediately after the occurrence of the failure in the transmission path, and the operation mode can be quickly switched.

According to the present invention, when the operation state of a computer changes, a predetermined first waveform is superimposed on a signal whose state changes among signals representing the operation state of the computer,
After superimposing a predetermined second waveform on a signal whose state does not change in synchronization with the first waveform, a signal representing an operation state of the computer is supplied to the monitoring device via a transmission line, and the computer operates in the control mode. When the first waveform or the second waveform is detected from any of the signals supplied through the transmission path from
If the first waveform or the second waveform is not detected from any of the other signals, it is determined that a failure has occurred in the transmission path to the computer, the operation mode of the computer is changed to the standby mode, Since the configuration is such that the operation mode of the computer operating in the standby mode is changed to the control mode, the number of switching of the value of each signal is reduced, and the life of the relay can be extended.

According to the present invention, one computer and the monitoring device, the other computer and the monitoring device, and the one computer and the other computer are electrically connected in order for each predetermined period. There is an effect that a cable for directly connecting computers can be omitted, and a transmission line for connecting devices can be simplified.

According to the present invention, only one computer and the other computer are electrically connected to each other when the monitoring device fails, so that if the monitoring device fails, the monitoring device can be quickly and quickly connected. There is an effect that the computers can be electrically connected reliably.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a dual monitoring system according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration example of a state change signal generation unit provided in each computer of the dual monitoring system according to the first embodiment;

FIG. 3 is a timing chart showing various signals when a failure occurs in a first computer in the first embodiment.

FIG. 4 is a timing chart showing various signals when a failure occurs in a first computer in the first embodiment, for example, when a DIO cable is disconnected.

FIG. 5 is a block diagram showing a configuration of a dual monitoring system according to a second embodiment of the present invention.

FIG. 6 is a timing chart showing various signals when a failure occurs in a first computer in the second embodiment.

FIG. 7 is a timing chart showing various signals when, for example, a DIO cable is disconnected when a failure occurs in a first computer in the second embodiment.

FIG. 8 is a timing chart showing various signals when a failure occurs in a first computer in the third embodiment.

FIG. 9 is a timing chart showing various signals when a failure occurs in a first computer in the third embodiment, for example, when a DIO cable is disconnected.

FIG. 10 is a timing chart showing various signals when a failure occurs in a first computer in the fourth embodiment.

FIG. 11 is a timing chart showing various signals when a failure occurs in a first computer in the fourth embodiment, for example, when a DIO cable is disconnected.

FIG. 12 is a block diagram showing a configuration of a dual monitoring system according to a fifth embodiment of the present invention.

13 is a block diagram illustrating a configuration example of a connection switching unit in FIG.

FIG. 14 is a timing chart showing a control signal supplied to a switch from a control signal output unit of a connection switching unit in the dual system monitoring device.

FIG. 15 is a block diagram showing a configuration of a connection switching unit in the dual monitoring system according to the sixth embodiment.

FIG. 16 is a timing chart showing a control signal supplied to a switch of the connection switching unit when a failure occurs in the dual system monitoring device.

FIG. 17 is a configuration diagram showing a conventional dual system monitoring system.

FIG. 18 is a block diagram illustrating a configuration example of a system to which a dual monitoring system is applied.

FIG. 19 is a timing chart showing various signals when a failure occurs in a first computer in a conventional apparatus.

FIG. 20 is a timing chart showing various signals when, for example, a DIO cable is disconnected when a failure occurs in a first computer in a conventional apparatus.

[Explanation of symbols]

1 1st system computer (computer), 2nd system computer (computer), 3 dual system monitoring device (monitoring device), 112 connection switching part.

Claims (10)

[Claims] 1. Two computers operating in a control mode on one side and in a standby mode on the other side, and those computers are monitored via a predetermined transmission line, and a failure occurs in the computer operating in the control mode. In the dual system monitoring system, comprising: a monitoring device that changes the operation mode of the computer in which the failure has occurred to the standby mode and changes the operation mode of the computer that operates in the standby mode to the control mode. A first signal indicating its own operation state is supplied to the monitoring device via the transmission line, and a second signal indicating whether or not any of the first signals has changed state is output. Supply to the monitoring device, when the monitoring device detects that a state of any of the first signals has changed based on the second signal from a computer operating in the control mode. If the state of any of the first signals supplied via the transmission line has not changed, it is determined that a failure has occurred in the transmission line with the computer, and the operation mode of the computer is changed. A dual system monitoring system, wherein the system is changed to a standby mode, and an operation mode of a computer operating in the standby mode is changed to a control mode. 2. A computer operating in the control mode and the other computer operating in the standby mode. The two computers are monitored via a predetermined transmission line, and a failure occurs in the computer operating in the control mode. In the dual system monitoring system, comprising: a monitoring device that changes the operation mode of the computer in which the failure has occurred to the standby mode and changes the operation mode of the computer that operates in the standby mode to the control mode. A first signal representing its own operating state is superimposed with a predetermined waveform every predetermined period, and a signal generated by superimposition is supplied to the monitoring device via the transmission line, and the monitoring device includes: If the predetermined waveform is not detected from a signal supplied from the computer operating in the control mode via the transmission line, it is determined that a failure has occurred in the transmission line to the computer, and the total is calculated. Dual system monitoring system, characterized in that to change the operation mode of the machine to the standby mode, changing the operation mode of the computer operating in the standby mode to control mode. 3. Two computers operating in the control mode and the other operating in the standby mode, and those computers are monitored via a predetermined transmission line, and a failure occurs in the computer operating in the control mode. In the dual system monitoring system, comprising: a monitoring device that changes the operation mode of the computer in which the failure has occurred to the standby mode and changes the operation mode of the computer that operates in the standby mode to the control mode. A signal having a cycle according to its own operation state is supplied to the monitoring device via the transmission line, and the monitoring device transmits a signal supplied from the computer operating in the control mode via the transmission line with a direct current. If so,
Judging that a failure has occurred in the transmission path between the computer and the computer, changing the operation mode of the computer to a standby mode, and changing the operation mode of a computer operating in the standby mode to a control mode. Dual system monitoring system. 4. A computer which operates in the control mode and the other computer operates in the standby mode, and monitors the computers via a predetermined transmission line, and a failure occurs in the computer operating in the control mode. In the dual system monitoring system, comprising: a monitoring device that changes the operation mode of the computer in which the failure has occurred to the standby mode and changes the operation mode of the computer that operates in the standby mode to the control mode. When the own operation state changes, of the signals representing the own operation state, a predetermined first waveform is superimposed on a signal whose state changes, and a predetermined second waveform is superimposed on a signal whose state does not change. After superimposing in synchronization with the first waveform,
Supplying a signal representing the operation state of the own device to the monitoring device via the transmission line, wherein the monitoring device receives the signal from any of the signals supplied via the transmission line from a computer operating in the control mode; If the first waveform or the second waveform is detected, and if the first waveform or the second waveform is not detected from any of the other signals, a failure occurs in the transmission path to the computer. A dual system monitoring system, which determines that an error has occurred, changes the operation mode of the computer to the standby mode, and changes the operation mode of the computer operating in the standby mode to the control mode. 5. A connection switching unit for electrically connecting one computer and the monitoring device, the other computer and the monitoring device, and the one computer and the other computer in order for each predetermined period. The dual system monitoring system according to any one of claims 1 to 4, characterized in that: 6. The dual monitoring system according to claim 5, wherein the connection switching unit electrically connects only one computer and the other computer when the monitoring device fails. 7. When two computers operating in the control mode and one operating in the standby mode are monitored by a predetermined monitoring device via a predetermined transmission line, and a failure occurs in the computer operating in the control mode. A dual system monitoring method for changing the operation mode of a computer in which a failure has occurred to a standby mode and changing the operation mode of a computer operating in the standby mode to a control mode, comprising: A signal is supplied to the monitoring device via the transmission line, and a second signal indicating whether a state of any of the first signals has changed.
Supplying the signal of the above to the monitoring device, when it is detected that the state of any of the first signal has changed based on the second signal from the computer operating in the control mode, If the state of any of the first signals supplied via the transmission line has not changed, it is determined that a failure has occurred in the transmission line with the computer, and the operation mode of the computer is set to a standby mode. And the operation mode of the computer operating in the standby mode is changed to the control mode. 8. When two computers operating in the control mode and the other operating in the standby mode are monitored by a predetermined monitoring device via a predetermined transmission line, and a failure occurs in the computer operating in the control mode. A dual system monitoring method for changing the operation mode of a computer in which a failure has occurred to a standby mode and changing the operation mode of a computer operating in the standby mode to a control mode, comprising: On the signal, a predetermined waveform is superimposed every predetermined period, a signal generated by superimposition is supplied to the monitoring device via the transmission line, and a computer operating in the control mode via the transmission line If the predetermined waveform is not detected from the supplied signal, it is determined that a failure has occurred in the transmission line with the computer, the operation mode of the computer is changed to a standby mode, and the standby mode is changed. Dual system monitoring method comprising changing the operating mode of the computer operating in de control mode. 9. When two computers operating in the control mode and one operating in the standby mode are monitored by a predetermined monitoring device via a predetermined transmission path, and a failure occurs in the computer operating in the control mode. In the dual system monitoring method of changing the operation mode of the computer in which the failure has occurred to the standby mode and changing the operation mode of the computer operating in the standby mode to the control mode, the cycle according to the operation state of the computer A signal is supplied to the monitoring device via the transmission line, and when a signal supplied from the computer operating in the control mode via the transmission line is DC, a failure occurs in the transmission line between the computer and the computer. And determining that an error has occurred, changing the operation mode of the computer to the standby mode, and changing the operation mode of the computer operating in the standby mode to the control mode. Law. 10. When two computers operating in the control mode and one operating in the standby mode are monitored by a predetermined monitoring device via a predetermined transmission line, and a failure occurs in the computer operating in the control mode. In the dual system monitoring method of changing the operation mode of the failed computer to the standby mode, and changing the operation mode of the computer operating in the standby mode to the control mode, when the operation state of the computer changes Of a signal representing an operating state of the computer, a predetermined first waveform is superimposed on a signal whose state changes, and a predetermined second waveform is synchronized with a signal whose state does not change in synchronization with the first waveform. After the superimposition, a signal representing the operation state of the computer is supplied to the monitoring device via the transmission line, and any of the signals supplied from the computer operating in the control mode via the transmission line is used. If the first waveform or the second waveform is not detected from any of the other signals when the first waveform or the second waveform is detected, a fault occurs in the transmission path between the computer and the computer. A dual system monitoring method, wherein it is determined that an error has occurred, the operation mode of the computer is changed to the standby mode, and the operation mode of the computer operating in the standby mode is changed to the control mode.