Redundant Systems

Abstract

This prevents both redundant modules from becoming the main system. [Solution] When periodic diagnostic information and a second elapsed time are received by the receiving unit 114 and the receiving unit 124 after the first switching unit 116 and the first switching unit 126 have switched their own module to the main system, the comparing unit 117 and the comparing unit 127 compare the first elapsed time with the second elapsed time, and when the comparing unit 117 and the comparing unit 127 finds that the first elapsed time is shorter than the second elapsed time, the second switching unit 118 and the second switching unit 128 switch their own module to the secondary system.

Description

[Technical Field]

[0001] The present invention relates to redundant systems. [Background technology]

[0002] In modules that configure redundant controllers, self-diagnosis information is transmitted from the master module, which performs control at a fixed cycle, to the standby slave module. If the slave module cannot receive the self-diagnosis information from the master module or detects an abnormality in the master module based on the self-diagnosis information, it transitions itself from a slave to a master module. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-012517 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-mentioned technology, even if the main module is in a healthy state, if communication with the secondary module is temporarily disrupted due to noise or the like, the self-diagnostic information will not be received, and the secondary module will transition to the main module, which could result in both modules becoming the main module.

[0005] The present invention has been made to solve the above problems, and aims to prevent a situation in which both of the two redundant modules become the main system. [Means for solving the problem]

[0006] The redundant system of the present invention is a redundant system that includes at least two, a first module and a second module, each configured to connect to a network and perform control operations to control a control object, and each of the first module and the second module includes a diagnostic unit configured to diagnose the state of the first module, a measurement unit configured to measure a first elapsed time since the first module is switched to the primary system, a transmission unit configured to periodically transmit to the other module the diagnostic information diagnosed by the diagnostic unit and the first elapsed time measured by the measurement unit, a receiving unit configured to periodically receive the diagnostic information and the second elapsed time transmitted from the other module, an abnormality determination unit that determines an abnormality in the other module when the receiver does not receive the periodic diagnostic information, a first switching unit configured to make the first module the primary system when the abnormality determination unit determines an abnormality in the other module, a comparison unit configured to compare the first elapsed time with the second elapsed time when the receiver receives the periodic diagnostic information and the second elapsed time after the first switching unit switches the first module to the primary system, and a second switching unit that switches the first module to the secondary system when the comparison unit determines that the first elapsed time is shorter than the second elapsed time.

[0007] In one example of the configuration of the redundant system described above, the abnormality determination unit detects an abnormality in another module from diagnostic information transmitted from the other module and determines whether the other module is abnormal.

[0008] In one example configuration of the redundant system, each of the first module and the second module includes a control unit for controlling a control target.

[0009] In one example of the configuration of the redundant system, the control unit generates control data for controlling the controlled object and sends it to the controlled object. [Effects of the Invention]

[0010] As described above, according to the present invention, if the first elapsed time since the module was switched to the primary system is shorter than the second elapsed time transmitted from the other module, the module is switched to the secondary system, thereby preventing a situation in which both of the two redundant modules become the primary system. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of a redundant system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart illustrating an example of the operation of the redundant system according to the embodiment of the present invention. [Figure 3] FIG. 3 is a configuration diagram showing the hardware configuration of a redundant system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] A redundant system according to an embodiment of the present invention will be described below with reference to Fig. 1. This redundant system includes two redundant modules, a first module 101 and a second module 102, which are connected to a network 103 and perform control operations to control a field device 104 to be controlled. Although the figure shows one field device 104, multiple field devices can be connected to the network 103.

[0013] The first module 101 includes a diagnosis unit 111 , a measurement unit 112 , a transmission unit 113 , a reception unit 114 , an abnormality determination unit 115 , a first switching unit 116 , a comparison unit 117 , a second switching unit 118 , and a control unit 119 .

[0014] The second module 102 includes a diagnosis unit 121 , a measurement unit 122 , a transmission unit 123 , a reception unit 124 , an abnormality determination unit 125 , a first switching unit 126 , a comparison unit 127 , a second switching unit 128 , and a control unit 129 .

[0015] Diagnosis unit 111 and diagnosis unit 121 diagnose the state of their own modules. Measurement unit 112 and measurement unit 122 measure a first elapsed time since their own modules were switched to the primary system. Transmission unit 113 and transmission unit 123 periodically transmit the diagnosis information diagnosed by diagnosis unit 111 and diagnosis unit 121 and the first elapsed time measured by measurement unit 112 and measurement unit 122 to other modules.

[0016] The receiving units 114 and 124 periodically receive the diagnostic information and the second elapsed time transmitted from the other modules. The second elapsed time is the time elapsed since the other modules were switched to the primary system. The abnormality determination units 115 and 125 determine an abnormality in the other modules when the receiving units 114 and 124 do not periodically receive the diagnostic information. Furthermore, the abnormality determination units 115 and 125 detect an abnormality in the other modules from the diagnostic information transmitted from the other modules and determine an abnormality in the other modules.

[0017] When the abnormality determination unit 115 and the abnormality determination unit 125 determine that another module has an abnormality, the first switching unit 116 and the first switching unit 126 switch their own module to the primary system.

[0018] The comparison unit 117 and the comparison unit 127 compare the first elapsed time with the second elapsed time when the periodic diagnostic information and the second elapsed time are received by the receiving unit 114 and the receiving unit 124 after the first switching unit 116 and the first switching unit 126 have switched their own modules to the main system.

[0019] When the comparison by the comparison unit 117 and the comparison unit 127 shows that the first elapsed time is shorter than the second elapsed time, the second switching unit 118 and the second switching unit 128 switch their own modules to the secondary system.

[0020] The control unit 119 and the control unit 129 control the field device 104, which is the control target. The control unit 119 stores setting data for generating control data for controlling the field device 104, and generates the control data based on the stored setting data. The control unit 119 sends the generated control data to the field device 104 via the network 103.

[0021] As described above, according to the embodiment, if the first elapsed time since the module itself was switched to the primary system is shorter than the second elapsed time transmitted from the other module, the module itself is switched to the secondary system. The comparison between the first elapsed time and the second elapsed time by comparison unit 117 and comparison unit 127 occurs when both first module 101 and second module 102 are primary systems. According to the embodiment, this state is immediately resolved, making it possible to prevent a state in which both modules are primary systems.

[0022] Next, an example of operation of the redundant system (redundancy method) in the embodiment will be described with reference to Fig. 2. Below, an example of operation of the first module 101 will be described. Note that the second module 102 operates in the same way.

[0023] First, in step S101, diagnosis unit 111 diagnoses the state of its own module, and in step S102, measurement unit 112 measures a first elapsed time since its own module was switched to the primary system. Next, in step S103, transmission unit 113 periodically transmits the diagnosis information diagnosed by diagnosis unit 111 and the first elapsed time measured by measurement unit 112 to the other module. Next, in step S104, reception unit 114 periodically receives the diagnosis information and the second elapsed time transmitted from the other module.

[0024] Next, in step S105, the abnormality determination unit 115 determines whether an abnormality has occurred. If the abnormality determination unit 115 determines that an abnormality has not occurred in the other module (no in step S105), the process returns to step S101. On the other hand, if the abnormality determination unit 115 determines that an abnormality has occurred in the other module (yes in step S105), in step S106, the first switching unit 115 sets its own module as the primary system.

[0025] Next, in step S107, the comparison unit 117 determines whether or not the periodic diagnostic information and the second elapsed time have been received by the receiving unit 114. If the periodic diagnostic information and the second elapsed time have been received (yes in step S107), the process returns to step S101. On the other hand, if the periodic diagnostic information and the second elapsed time have not been received (no in step S107), the comparison unit 117 compares the first elapsed time with the second elapsed time in step S108.

[0026] If the comparison shows that the first elapsed time is longer than the second elapsed time (no in step S108), the process returns to step S101. On the other hand, if the first elapsed time is shorter than the second elapsed time (yes in step S108), the second switching unit 118 switches its own module to the slave system in step S109. The above-mentioned steps S101 to S110 are continued until the control ends (step S110).

[0027] As shown in FIG. 3, the modules according to the above-described embodiments may be computer devices including a CPU (Central Processing Unit) 301, a main storage device 302, an external storage device 303, and a network connection device 304, and the above-described functions (redundancy methods) may be realized by the CPU 301 operating (executing) a program loaded in the main storage device 302. The above-described program is a program for causing a computer to execute the redundancy methods described in the above-described embodiments. The network connection device 304 is connected to a network 305. The functions may also be distributed among multiple computer devices.

[0028] As described above, according to the embodiment of the present invention, if the first elapsed time since the module was switched to the primary system is shorter than the second elapsed time transmitted from the other module, the module is switched to the secondary system, thereby preventing a situation in which both of the two redundant modules become the primary system.

[0029] It should be noted that the present invention is not limited to the embodiments described above, and it is clear that many modifications and combinations can be made by a person having ordinary knowledge in the art within the technical concept of the present invention. [Explanation of symbols]

[0030] 101...first module, 102...second module, 103...network, 104...field device, 111,121...diagnostic unit, 112,122...measurement unit, 113,123...transmitting unit, 114,124...receiving unit, 115,125...abnormality determination unit, 116,126...first switching unit, 117,127...comparison unit, 118,128...second switching unit, 119,129...control unit.

Claims

1. A redundant system including at least two first and second modules, each configured to connect to a network and perform a control operation for controlling a control object, Each of the first module and the second module comprises: a diagnostic unit configured to diagnose the state of its own module; a measurement unit configured to measure a first elapsed time since the module itself was switched to the primary system; a transmitting unit configured to periodically transmit to another module the diagnostic information diagnosed by the diagnosing unit and the first elapsed time measured by the measuring unit; a receiving unit configured to periodically receive the diagnostic information and the second elapsed time transmitted from the other module; an abnormality determination unit that determines an abnormality in another module when the receiving unit does not receive periodic diagnostic information; a first switching unit configured to set its own module as a primary system when the abnormality determination unit determines an abnormality in another module; a comparison unit configured to compare the first elapsed time with the second elapsed time when the periodic diagnostic information and the second elapsed time are received by the receiving unit after the first switching unit switches its own module to the primary system; a second switching unit that switches its own module to a secondary system when the first elapsed time is shorter than the second elapsed time as a result of the comparison by the comparing unit; A redundant system comprising:

2. 2. The redundant system of claim 1, The abnormality determination unit is a redundant system that detects abnormalities in other modules from diagnostic information transmitted from the other modules and determines whether the other modules are abnormal.

3. 3. The redundant system according to claim 1, A redundant system in which the first module and the second module each include a control unit for controlling the controlled object.

4. 4. The redundant system of claim 3, The control unit is a redundant system that generates control data for controlling the controlled object and sends it to the controlled object.

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