JP2015011371A - Alternative control apparatus, alternative control method, and alternative control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alternative control apparatus which is connected to a signal source and allows a master device to obtain data from the signal source even if a fault occurs in an apparatus for transmitting the data from the signal source to the master device via a bus.SOLUTION: An alternative control apparatus is connected to a signal source via signal connection means and connected to a bus, and includes: fault detection means which detects a faulty device where a fault occurs, from among a plurality of devices for transmitting data based on a signal from the signal source in response to a received instruction, via the bus; alternative instruction means which transmits an alternative operation instruction to an alternative device which is a specific device other than the faulty device and receives and executes an instruction to the faulty device on receipt of the alternative operation instruction; and connection control means which transmits a switching instruction to the signal connection means which connects the signal source connected to the faulty device to the alternative device, on receipt of the switching instruction.

Description

  The present invention relates to a technique for replacing a device in which a failure has occurred.

  Patent Literature 1 describes a serial bus system including a plurality of slave devices and a master device. The master device and the plurality of slave devices are connected to the same serial bus. This master device identifies the slave device that has hung up. Then, the master device resets the identified slave device by transmitting a reset signal.

  Cited Document 2 describes a bus system including a master device and a plurality of slave devices. The master device is connected to two I2C (Inter-Integrated Circuit) buses. When no failure is detected in the I2C bus, each slave device is connected to one of the two I2C buses via a switch that determines a connection destination I2C bus. When a failure is detected in the I2C bus, the master device connects the slave devices one by one to the other I2C bus to identify the slave device that is the cause of the failure. The master device attempts to recover the slave device by resetting the specified slave device to disconnect and reconnect the specified slave device to the power source. When the slave device recovers, the master device connects the slave device to the original I2C bus again. If the slave device does not recover, the master device disconnects the connection between the slave device and the power source.

  Patent Document 3 describes a bus connection circuit that is connected between a peripheral component that is a slave device and an I2C bus. The bus connection circuit detects whether or not peripheral parts connected to the bus connection circuit are in an abnormal state. When it is detected that the peripheral component connected to the bus connection circuit is in an abnormal state, the bus connection circuit disconnects the peripheral component from the I2C bus.

  Patent Document 4 describes an I2C bus communication control system that identifies a slave device that is the cause of a freeze based on a slave address when the I2C bus freezes. The I2C bus communication control system restores the I2C bus from the freeze by resetting only the specified slave device.

  Japanese Patent Application Laid-Open No. H10-228561 describes a duplex device that is configured by a basic device and a backup device connected to a processor via a bus. The processor identifies and controls the basic device and the backup device by a unique device address. When a failure occurs in the basic device, the backup device converts the device address of the backup device into the device address of the basic device.

  Patent Document 6 describes a printer that is a slave device connected to an image supply device that is a master device via a 1394 serial bus. The image supply device transmits image data to the printer. When an error is detected in the data transfer, the image supply device retransmits the data.

JP 2010-055472 A JP 2003-242048 A JP 2012-068907 A JP 2012-150749 A Japanese Patent Laid-Open No. 01-162942 JP-A-10-322414

  The slave device connected to the master device via the bus has a slave device that transmits data representing signals from sensors and other signal sources connected to the slave device to the master device via the bus. is there.

  When a failure is detected in a slave device, the master device of Patent Document 1 transmits a reset signal to the slave device. However, the master device cannot obtain data from the signal source connected to the slave device until the reset slave device starts operating normally. If the slave device does not operate normally even if it is reset, the master device cannot obtain data from the signal source connected to the slave device.

  When a failure is detected in a slave device, the master device of Patent Document 2 resets the slave device. Therefore, the master device cannot obtain data from the signal source connected to the slave device until the reset slave device starts operating normally. If the slave device does not operate normally even if it is reset, the master device disconnects the slave device from the power source. Therefore, in this case, the master device cannot obtain data from the signal source connected to the slave device.

  When a failure is detected in a slave device, the bus connection circuit of Patent Literature 3 disconnects the slave device from the I2C bus. Therefore, the master device connected to the I2C bus cannot obtain data from the signal source connected to the slave device.

  The I2C bus communication control system of Patent Document 4 resets only the slave device identified as the cause of the bus freeze. Accordingly, the master device connected to the bus cannot obtain data from the signal source connected to the slave device until the reset slave device starts operating normally. If the slave device does not operate normally even if it is reset, the master device cannot obtain data from a signal source connected to the slave device.

  The backup device of Patent Document 5 operates by converting the address of the basic device of the backup device when the basic device fails. Thus, if a failure occurs in a basic device, the processor cannot obtain data from a signal source connected to that basic device.

  When an error is detected in the data transfer, the image supply device of Patent Document 6 retransmits the data to the printer. However, if the image supply device fails, the printer cannot obtain data from the image supply device.

  As described above, in the techniques of Patent Documents 1 to 6, when a failure occurs in a slave device connected to a master device via a bus, the master device is a signal source connected to the slave device in which the failure occurs. Data representing the signal from cannot be obtained.

  One of the objects of the present invention is that even when a failure occurs in a device connected to a signal source and transmitting data from the signal source to the master device via a bus, the master device transmits the data from the signal source. It is to provide an alternative control device that can be obtained.

  The alternative control device of the present invention is connected to the signal source through the signal connecting means and connected to the bus, and returns data based on the signal from the signal source to the received command via the bus. A failure detecting means for detecting a failed device having a failure from a plurality of devices, and a specific device other than the failed device among the plurality of devices, and receiving an instruction for the failed device upon receiving an alternative operation instruction And an alternative instruction means for transmitting the alternative operation instruction to the alternative device to be executed, and the signal connection for connecting the signal source connected to the failed device to the alternative device when receiving the switching instruction Means for transmitting the switching instruction.

  The alternative control method of the present invention is connected to a signal source through a signal connection means and connected to a bus, and returns data based on the signal from the signal source to the received command via the bus. When a faulty device in which a fault has occurred is detected from a plurality of devices and a specific device other than the faulty device among the plurality of devices is received and an alternative operation instruction is received, a command for the faulty device is received and executed. When the substitute operation instruction is transmitted to the substitute device and the switch instruction is received, the switch source is transmitted to the signal connection unit that connects the signal source connected to the faulty device to the substitute device. To do.

  The alternative control program of the present invention is a computer connected to a signal source via a signal connection means and connected to a bus, and data based on a signal from the signal source with respect to a command received via the bus. A failure detection means for detecting a faulty device in which a fault has occurred from a plurality of devices that send back, and a specific device other than the faulty device among the plurality of devices, and when an alternative operation instruction is received, An alternative instruction means for transmitting the alternative operation instruction to an alternative device that receives and executes the instruction, and when the switching instruction is received, the signal source connected to the faulty device is connected to the alternative device. The signal connection means is operated as connection control means for transmitting the switching instruction.

  In the present invention, even when a failure occurs in a device connected to a signal source and transmitting data from the signal source to the master device via a bus, the master device can obtain data from the signal source. There is an effect.

FIG. 1 is a block diagram illustrating the configuration of the information processing system according to the first embodiment. FIG. 2 is a block diagram illustrating another example of the configuration of the information processing system 100 according to the first embodiment. FIG. 3 is a block diagram illustrating an example of the configuration of the bus connection unit 31. FIG. 4 is a block diagram illustrating an example of the configuration of the bus connection unit 31. FIG. 5 is a block diagram illustrating another example of the configuration of the bus connection unit 31. FIG. 6 is a block diagram illustrating an example of the configuration of the signal connection unit 33. FIG. 7 is a block diagram illustrating an example of the configuration of the signal connection unit 33. FIG. 8 is a block diagram illustrating another example of the configuration of the signal connection unit 33. FIG. 9 is a diagram illustrating an example of a specific connection between the bus 2 and devices connected to the bus 2 when the bus 2 is an I2C bus. FIG. 10 is a flowchart showing an example of the operation when the faulty device is detected by the alternative control device 1 of the first and second embodiments. FIG. 11 is a block diagram illustrating an example of a configuration of an information processing system 100A according to the second embodiment. FIG. 12 is a flowchart illustrating the operation of the alternative device 1A according to the second embodiment during the failed device recovery process. FIG. 13 is a block diagram illustrating an example of a configuration of an alternative control device 1B according to the third embodiment. FIG. 14 is a diagram illustrating an example of a configuration of a computer 1000 used to realize the alternative control device 1, the alternative control device 1A, and the alternative control device 1B.

  Next, a first embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram illustrating an example of a configuration of an information processing system 100 according to the present embodiment.

  Referring to FIG. 1, the information processing system 100 includes an alternative control device 1, a device 32 </ b> A, a device 32 </ b> B, and a control device 4. In the example of FIG. 1, the number of devices is two, but the number of devices is not limited to the example of FIG. The number of devices may be three or more. The substitutability control device 1 is connected to a bus 2. Each device is connected to the bus 2 via the bus connection unit 31. Each device is connected to a signal source via a signal connection unit 33. In the example of FIG. 1, the signal sources are a signal source 34A and a signal source 34B. The bus connection unit 31 may be included in the alternative control device 1. The signal connection unit 33 may also be included in the alternative control device 1. In the example of FIG. 1, the control device 4 is connected to the bus 2 via the alternative control device 1.

  The substitution control device 1 includes a failure detection unit 10, a connection control unit 11, a substitution instruction unit 12, a command transmission unit 13, and a command storage unit 14.

  The signal source is, for example, a temperature sensor, a sensor that measures the rotational speed of the fan, or another sensor. The signal source may be, for example, a storage device that stores some data.

  The device converts a signal from a signal source connected to the device into data. When the device receives a data read command from the control device 4 for the device via the bus 2, the device outputs data representing a signal from the signal source to the bus 2. Hereinafter, a data read command is simply referred to as a command. The command is transmitted to each device connected to the bus 2. The instruction includes the address of the device targeted by the instruction. When the received command includes an address set as the address of the device, the device that has received the command returns a response to the received command. Even if the device receives the command, if the received command does not include the address set in the device, the device does not execute the received command. The device address only needs to be set in advance. Further, as will be described later, the substitution instruction unit 12 can change the device address.

  FIG. 2 is a block diagram illustrating another example of the configuration of the information processing system 100 according to the present embodiment. In the example of FIG. 2, the control device 4 is directly connected to the bus 2. As described above, the control device 4 may be directly connected to the bus 2.

  The bus connection unit 31 connects each device and the bus 2 in the initial state. Furthermore, the bus connection unit 31 individually disconnects the connection between each device and the bus 2 based on an instruction from the connection control unit 11. In addition, the bus connection unit 31 connects a device not connected to the bus 2 and the bus 2 based on an instruction from the connection control unit 11.

  FIG. 3 is a block diagram illustrating an example of the configuration of the bus connection unit 31. In the example of FIG. 3, the bus connection unit 31 includes a switch 311A and a switch 311B. In the example of FIG. 3, there are the same number of switches as the number of devices. Each switch is connected to one of the devices and the bus 2. That is, all devices are connected to one of the switches. Note that the number of switches may be different from the number of devices. For example, there may be a device connected to the bus 2 without going through the bus connection unit 31. However, when a failure is detected in a device directly connected to the bus 2, the operation in step S104 shown in FIG. 10 described later is not performed. When the switch is in a connected state, the device connected to the switch and the bus 2 are connected. When the switch is in the open state, the connection between the device connected to the switch and the bus 2 is disconnected. In the example of FIG. 3, all the switches are connected. The bus connection unit 31 controls, for each switch, whether the switch is in a connected state or an open state based on an instruction from the connection control unit 11.

  For example, the switch 311A is connected to the device 32A and the bus 2. When the switch 311A is in the connected state, the device 32A and the bus 2 are connected. When the switch 311A is in an open state, the connection between the device 32A connected to the switch 311A and the bus 2 is disconnected. The switch 311B is connected to the device 32B and the bus 2. When the switch 311B is in the connected state, the device 32B and the bus 2 are connected. When the switch 311B is in the open state, the connection between the device 32A connected to the switch 311B and the bus 2 is disconnected.

  FIG. 4 is a block diagram illustrating an example of the configuration of the bus connection unit 31. The configuration of the bus connection unit 31 shown in FIG. 4 is the same as the configuration of the bus connection unit 31 shown in FIG. However, in the example of FIG. 4, the switch 311A connected to the device 32A is in an open state.

  FIG. 5 is a block diagram illustrating another example of the configuration of the bus connection unit 31. In the example of FIG. 5, the bus connection unit 31 is realized by a bus connection unit 31A and a bus connection unit 31B. As described above, the bus connection unit 31 may be realized by a bus connection unit divided into a plurality of parts. Then, as in the example shown in FIG. 5, one bus connection unit may be connected to one device and the bus 2. In the example illustrated in FIG. 5, the bus connection unit 31 </ b> A including the switch 311 </ b> A is connected to the device 32 </ b> A and the bus 2. A bus connection unit 31B including the switch 311B is connected to the device 32B and the bus 2.

  In an initial state, the signal connection unit 33 connects between a device and a signal source assigned to the device. Furthermore, the signal connection unit 33 switches the signal source connected to the device to another signal source based on an instruction from the connection control unit 11.

  FIG. 6 is a block diagram illustrating an example of the configuration of the signal connection unit 33. In the example illustrated in FIG. 6, the signal connection unit 33 includes a switch 331A and a switch 331B. The switch 331A is connected to the device 32A, the signal source 34A, and the signal source 34B. The switch 331A connects either the signal source 34A or the signal source 34B to the device 32A. The switch 331B is connected to the device 32B, the signal source 34A, and the signal source 34B. The switch 331B connects either the signal source 34A or the signal source 34B to the device 32B. The number of switches included in the signal connection unit 33 may be three or more. The number of signal sources connected to one switch may be three or more. Each switch connects any of the signal sources connected to that switch to the device connected to that switch. Each switch may be in an open state in which no signal source is connected to the device. The signal connection unit 33 controls the state of each switch based on the signal received from the connection control unit 11.

  In the initial state, the signal connection unit 33 connects the signal source 34A to the device 32A as in the example illustrated in FIG. The signal connection unit 33 connects the signal source 34B to the device 32B.

  FIG. 7 is a block diagram illustrating an example of the configuration of the signal connection unit 33. In the example of FIG. 7, the signal connection unit 33 connects the signal source 34A to the device 32B. The signal connection unit 33 connects the signal source 34B to the device 32A. The signal connection unit 33 may switch between the state illustrated in FIG. 6 and the state illustrated in FIG. 7 based on the signal received from the connection control unit 11.

  FIG. 8 is a block diagram illustrating another example of the configuration of the signal connection unit 33. In the example of FIG. 8, the signal connection unit 33 is realized by a signal connection unit 33A including a switch 331A and a signal connection unit 33B including a switch 331B. Thus, the signal connection unit 33 may be realized by a signal connection unit divided into a plurality of parts.

  The bus 2 is a bus realized by, for example, an I2C bus. The bus 2 may be another bus as long as it is a bus to which a device that operates as a master device and a plurality of devices that operate as slave devices are connected.

  FIG. 9 is a diagram illustrating an example of a specific connection between the bus 2 and devices connected to the bus 2 when the bus 2 is an I2C bus. The bus 2 is realized by an SDA (Serial Data) 2A that is a serial data line and an SCL (Serial Clock) 2B that is a serial clock line. Alternative control device 1 is connected to SDA 2A and SCL 2B. Each device is connected to SDA 2A and SCL 2B via a bus connection unit. In the example of FIG. 9, one device is connected to the SDA 2A and SCL 2B via one bus connection unit. SDA2A and SCL2B are pulled up by the power supply VDD in order to keep the signal high when the bus 2 is not used.

  The control device 4 can communicate with each device connected to the bus 2. The control device 4 outputs an instruction to the bus 2. The instruction includes the address of a device that executes the instruction. For example, if bus 2 is an I2C bus, the instruction is an I2C command. Then, the command is transmitted to all devices connected to the bus 2.

  The device that has received the command transmits a response to the command via the bus 2 when the address of the device is included in the received command. As described above, in the present embodiment, the command for the device transmitted by the control device 4 is a data read command representing a signal from a signal source connected to the device. In the example of FIG. 1, each device transmits data representing a signal from a signal source connected to the device to the bus 2 as a response.

  The control device 4 receives a response to the command from the device that transmitted the command.

  When the control device 4 is connected to the bus 2 via the alternative control device 1 as in the example of FIG. 1, for example, the command transmission unit 13 of the alternative control device 1 receives a command from the control device 4. Then, the command transmission unit 13 stores the received command in the command storage unit 14. Further, the command transmission unit 13 outputs the received command to the bus 2. When receiving a response to the output command from the bus 2, the command transmission unit 13 transmits the received response to the control device 4.

  As in the example of FIG. 2, when the control device 4 is connected to the bus 2, the control device 4 directly outputs a command to the bus 2. The control device 4 directly receives a response from the bus 2. Then, the command transmission unit 13 receives the command output from the control device 4 to the bus 2 from the bus 2. Then, the command transmission unit 13 stores the received command in the command storage unit 14.

  Further, the command transmission unit 13 may detect a response to the command transmitted to the bus 2. Then, the command transmission unit 13 may delete the command for which a response has been detected from the command storage unit 14.

  The command storage unit 14 stores the command transmitted by the control device 4.

  The failure detection unit 10 detects a device in which a failure has occurred from each device. In the description of this embodiment and other embodiments, a device detected by the failure detection unit 10 is referred to as a detection device.

  The substitute instruction unit 12 transmits an substitute operation instruction to the substitute device. The alternative device is a device other than the detection device that is the detected device. When the substitute device receives the substitute operation instruction, the substitute device receives and executes a command for the detection device.

  The connection control unit 11 transmits a switching instruction to the signal connection unit 33. When the signal connection unit 33 receives the switching instruction, the signal connection unit 33 connects the signal source connected to the detection device to the alternative device. When the detection device is detected, the connection control unit 11 transmits a disconnection instruction to the bus connection unit 31. When receiving the disconnection instruction, the bus connection unit 31 disconnects the connection between the bus 2 and the detection device.

  The command transmission unit 13 outputs a command for the detection device, which is stored in the command storage unit 14, to the bus 2 when an alternative operation instruction and a turn-back time are transmitted.

  Next, the operation of this embodiment will be described.

  FIG. 10 is a flowchart showing an example of the operation when the faulty device is detected by the alternative control apparatus 1 of the present embodiment.

  The command transmission unit 13 stores the command transmitted to the bus 2 by the control device 4 in the command storage unit 14 (step S101).

  As described above, when the control device 4 transmits a command to the bus 2 via the command transmission unit 13, the command transmission unit 13 stores the command received from the control device 4 in the command storage unit 14. When the control device 4 directly transmits a command to the bus 2, the command transmission unit 13 may receive a command transmitted to the bus 2 and store it in the command storage unit 14.

  Next, the failure detection unit 10 detects a device in which a failure has occurred (step S102).

  For example, the failure detection unit 10 measures the time after the command is transmitted with a timer. At this time, for example, the command transmission unit 13 may detect a response to the transmitted command. Then, when a response to the command is not detected within a predetermined time after the command is transmitted, the failure detection unit 10 determines that a failure has occurred in the device including the address in the command.

  If a response to the command is detected within a predetermined time after the command is transmitted, no failure has occurred in the device whose address is included in the command. In this case, no faulty device is detected. Further, in this case, the command transmission unit 13 may associate data indicating that a response has been detected with a command stored in the command storage unit 14 and for which a response has been detected. Alternatively, the command transmission unit 13 may delete the command for which a response has been detected from the command storage unit 14.

  If no faulty device is detected (No in step S103), the command transmission unit 13 waits until the next command is transmitted.

  If a faulty device is detected (Yes in step S103), the connection control unit 11 transmits a disconnection instruction for disconnecting the faulty device from the bus to the bus connection unit 31.

  The disconnection instruction may include an identifier of the failed device. The bus connection unit 31 that has received the disconnection instruction disconnects the connection between the bus 2 and the failed device. When the bus connection unit 31 is configured to switch the switch associated with the identifier between the connected state and the disconnected state every time the device identifier is received, the disconnection instruction is the fault device identifier itself. There may be. As shown in FIG. 5, when one bus connection unit is connected to one device, the connection control unit 11 transmits a signal indicating a disconnection instruction to the bus connection unit connected to the failed device. That's fine. The bus connection unit 31 that has received the disconnection instruction disconnects the connection between the bus 2 and the faulty device, for example, by turning off a switch that connects the bus 2 and the faulty device.

  When a failure is detected in the device 32A, the connection control unit 11 transmits, for example, a disconnection instruction including the identifier of the device 32A to the bus connection unit 31. The bus connection unit 31 that has received the disconnection instruction disconnects the connection between the bus 2 and the device 32A by, for example, turning off the switch 311A. When the bus connection unit 31 is configured as in the example illustrated in FIG. 3, the state of the bus connection unit 31 that has received the disconnection instruction is changed from the state illustrated in FIG. 3 to the state illustrated in FIG. 4.

  For example, if a failure device has a failure that causes SDA or SCL to be in a low state, if the failure device and the bus 2 are connected, the bus 2 is connected between the control device 4 and another device. Communication is not possible. Even if such a failure has occurred by disconnecting the faulty device from the bus 2 by the bus connection unit 31, communication between the control device 4 and another device via the bus 2 can be performed. It becomes possible. If each device is designed not to put SDA or SCL in the low state, the alternative control device 1 does not have to perform the operation of step S104.

  Next, the substitution instruction unit 12 selects a device that is not a faulty device as a substitution device. Then, the alternative instruction unit 12 transmits an alternative operation instruction that is an instruction to execute an instruction to the faulty device to the alternative device (step S105). The substitute device that has received the substitute operation instruction responds to a command to the failed device. That is, it responds to an instruction including the address assigned to the failed device.

  The alternative operation instruction is, for example, a signal indicating an instruction to change an address assigned to the device. For example, the substitute instruction unit 12 transmits a signal representing an instruction to change the address to the address assigned to the failed device as an substitute operation instruction. The device that has received the alternative operation instruction changes the address of the device. The device then responds to an instruction that includes the changed address. Hereinafter, sending a signal indicating an instruction to change the address assigned to the device to the device is also referred to as setting an address in the device.

  The substitution instruction unit 12 may hold information representing a group of devices that perform the same operation by changing an address in advance. A device that performs the same operation by changing an address is, for example, a device that performs the same conversion on a signal from a signal source to generate data, and returns the generated data as a response. The information indicating the device group is, for example, a set of device identifiers. When a failure device is detected, the substitution instruction unit 12 may select a substitution device by an arbitrary method from devices included in the same group as the failure device.

  For example, when the control device 4 is configured to sequentially transmit a command to each device, the substitution instruction unit 12 may store the time at which the command for each device is transmitted. Then, the substitution instruction unit 12 may select a device having the shortest time elapsed since the latest command is transmitted as the substitution device. The substitution instruction unit 12 may count the number of times a command for the device is transmitted within a predetermined time in the past for each device. The substitution instruction unit 12 may store the counted number for each device. Then, the substitution instruction unit 12 may select a device having the smallest number of times the command has been transmitted as a substitution device. The substitution instruction unit 12 may calculate, for each device, an average time from when an instruction is transmitted to a device until the instruction is transmitted to the same device within a predetermined time in the past. The substitution instruction unit 12 may store the calculated average time for each device. Then, the substitution instruction unit 12 may select, as a substitution device, a device that is farthest from the current time at which the average time has elapsed since the most recent instruction was transmitted. In these cases, for example, the command transmission unit 13 may detect a command for each device. Then, the command transmission unit 13 may transmit a pair of the device identifier and the time when the command for the device is detected to the substitution instruction unit 12.

  Next, the connection control unit 11 transmits, to the signal connection unit 33, a switching instruction that is an instruction to connect the signal source connected to the failed device to the alternative device (step S106).

  When a signal source is connected to the alternative device when the switching instruction is transmitted, the signal connection unit 33 that has received the switching instruction disconnects the signal source connected to the alternative device from the alternative device. The signal connection unit 33 disconnects the signal source connected to the failed device from the failed device. Then, the signal connection unit 33 connects the signal source disconnected from the faulty device to the alternative device. The signal connection unit 33 may connect the signal source disconnected from the alternative device to the faulty device.

  The switching instruction is, for example, a signal including a combination of a faulty device identifier and an alternative device identifier. In that case, the signal connection unit 33 changes the connection state of the switch that connects the device and the signal source so that the signal sources connected to the two devices whose identifiers are included in the combination are switched.

  The switching instruction may be, for example, a signal representing a combination of a device identifier and a signal source identifier connected to the device. In that case, the connection control unit 11 transmits a signal representing a combination of the identifier of the alternative device and the identifier of the signal source connected to the failed device to the signal connection unit 33. The connection control unit 11 may further transmit a signal indicating an identifier of the faulty device and a signal indicating that the signal source is not connected to the signal connection unit 33. The connection control unit 11 may transmit a signal representing a combination of the identifier of the faulty device and the identifier of the signal source connected to the alternative device to the signal connection unit 33.

  For example, when the device 32B is an alternative device and the state of the signal connection unit 33 when the failed device is detected is the state illustrated in FIG. 6, the state of the signal connection unit that has received the switching instruction is, for example, FIG. It will be in the state shown in.

  The order of operations from step S104 to step S106 is not limited to the order shown in FIG. The alternative control device 1 may perform the operations of step S104, step S105, and step S106 in an order different from the order shown in FIG.

  Next, the command transmission unit 13 reads a command for the faulty device from the command storage unit 14 (step S107).

  It is desirable that the command transmission unit 13 reads only commands for which no response has been transmitted from the command storage unit 14. When a plurality of instructions for the faulty device are stored in the instruction storage unit 14, the instruction storage unit 14 reads the plurality of instructions from the instruction storage unit 14.

  Next, the command transmission unit 13 transmits the read command to the bus 2 (step S108).

  When a plurality of instructions are read, the instruction transmitting unit 13 may transmit the instructions to the bus 2 in the order in which the instructions are transmitted.

  The substitute device responds to the transmitted instruction for the failed device. As described above, if the instruction to be transmitted is an instruction to transmit data representing a signal from a signal source connected to the device, the alternative device transmits data representing the signal connected to the alternative device, Send as a response. The signal source connected to the alternative device is the signal source connected to the failed device when the failed device is detected. Therefore, the substitute device that has received the instruction for the failed device transmits data representing the signal from the signal source connected to the failed device as a response. As a result, the control device 4 can acquire data representing a signal from a signal source connected to a faulty device that does not respond to a command.

  Note that, for example, after the operation in step S108, when a command including an address set in the alternative device is transmitted when a failed device is detected, the alternative control device 1 may perform the operation in FIG. 10 again. The address of the failed device in that case is the address set as the alternative device when the failed device is detected in the first operation of FIG. As a result, for example, if there is no device that operates as a substitute device other than the substitute device in the first operation of FIG. 10, the address initially set in the substitute device is set. When there is a device that operates as an alternative device in addition to the alternative device in the operation of the first FIG. 10, a new alternative device is selected from the alternative device in the operation of the initial FIG. 10 and other devices that operate as the alternative device. Is done.

  In the present embodiment described above, even when a failure occurs in a device that is connected to a signal source and transmits data from the signal source to the control device 4 that is a master device via a bus, the control device 4 There is a first effect that data from the signal source can be obtained.

  This is because, when a failure device is detected by the failure detection unit 10, the substitution instruction unit 12 transmits an instruction to operate as a failure device to the selected substitution device. This causes the alternate device to respond to instructions for the failed device. This is because the connection control unit 11 connects the signal source connected to the failed device to the alternative device. Thereby, when the control device 4 transmits a command for transmitting data representing a signal from the signal source connected to the failed device to the failed device, the alternative device can respond. That is, the alternative device can transmit data representing the signal from the signal source that was connected to the failed device.

  The present embodiment further has an effect that the control device 4 can obtain a response to the command without retransmitting the command to the failed device that was transmitted when the failure was detected in the device. is there.

  The reason is that the command transmission unit 13 stores the command transmitted to the bus 2 to which each device is connected in the command storage unit 14. This is because after the alternative device starts to operate as a faulty device, the command transmission unit 13 reads a command for the faulty device for which no response has been detected from the command storage unit 14 and transmits the command.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 11 is a diagram illustrating a configuration of an information processing system 100A according to the present embodiment.

  Compared to the configuration of the information processing system 100 of the first embodiment shown in FIG. 1, the information processing system 100A includes an alternative control device 1A instead of the alternative control device 1.

  The alternative control device 1 </ b> A includes a reset unit 15 in addition to the components of the alternative control device 1.

  The reset unit 15 transmits a reset signal, which is a signal for instructing resetting, to the faulty device.

  Each device is reset when it receives a reset signal. That is, each device returns to the initial state when it receives the reset signal. The return of the device to the initial state means, for example, that the internal state of the device returns to the initial state. Each device returns to the initial state by, for example, restarting.

  The other components of the information processing system 100A are the same as those of the information processing system 100 according to the first embodiment to which the same numbers are assigned.

  Next, the operation of the alternative control device 1A of the present embodiment will be described in detail with reference to the drawings.

  The operation of the alternative control device 1A when detecting the faulty device is the same as the operation of the alternative control device 1 of the first embodiment shown in FIG. 10 when detecting the faulty device.

  FIG. 12 is a flowchart showing the operation of the alternative device 1A according to the present embodiment at the time of failure device recovery processing.

  In the present embodiment, the alternative control device 1A starts the operation of FIG. 12 with the faulty device disconnected from the bus 2 after the operation shown in FIG.

  First, the reset unit 15 transmits a reset signal to the faulty device (step S201).

  If the failed device is hung up for some reason, the failed device that received the reset signal is reset. That is, the faulty device returns to the initial state. For example, when the faulty device is hung up for some reason, the faulty device that has received the reset signal returns to the initial state by being restarted. If the faulty device is faulty and does not operate normally, the faulty device may not be reset upon receiving a reset signal. For example, if the faulty device is faulty and does not operate normally, the faulty device may not restart even if it receives a reset signal, and may not return to the initial state.

  Next, the connection control unit 11 transmits a connection instruction, which is an instruction to connect the failed device to the bus 2, to the bus connection unit 31 (step S202). The connection instruction is, for example, a signal for setting a switch to which the faulty device and the bus 2 are connected to each other.

  The operation in step S202 is a preparatory operation for confirming whether or not a failure that has occurred in the failed device has been resolved by transmitting a reset signal.

  By the time the operation of step S202 is performed, the substitution instruction unit 12 sets the address assigned to the failed device to the failed device, for example, the address set in the substitute device when the failed device is detected. A signal representing an instruction to change is transmitted. The address assigned to the failed device may be another address as long as it is different from the addresses assigned to other devices. Thus, if the failure of the failed device is eliminated, the address assigned to the failed device is changed.

  In addition, before the operation in step S202 is performed, the connection control unit 11 connects the signal source connected to the substitute device when the failed device is detected, for example, to the signal connection unit 33. Instructions may be sent. The connection control unit 11 may transmit an instruction to connect the signal source connected to the alternative device to the faulty device when the faulty device is detected, for example, when No in step S204 described later. .

  Next, the failure detection unit 10 detects whether or not the failed device has a failure (step S203).

  First, the failure detection unit 10 generates an instruction that specifies an address assigned to the failed device, that is, an instruction that includes an address assigned to the failed device. Next, the failure detection unit 10 transmits the generated instruction to the bus 2. The failure detection unit 10 may transmit the generated command via the command transmission unit 13. As described above, the address assigned to the failed device is different from the addresses assigned to other devices. The command transmitted to the bus 2 is transmitted to all devices connected to the bus 2. If the fault that has occurred in the faulty device has been resolved, the faulty device responds to the command generated by the fault detection unit 10. The fault detection unit 10 detects that the fault that has occurred in the faulty device has been resolved when there is a response within a predetermined time to the command generated by the fault detection unit 10. If the failure detection unit 10 does not respond to the command generated by the failure detection unit 10 within a predetermined time, the failure that has occurred in the failure device has not been resolved, and the failure device still has a failure. To detect.

  When the failure detection unit 10 detects that there is a failure (Yes in step S204), the connection control unit 11 transmits a disconnection instruction to disconnect the connection between the failed device and the bus 2 to the bus connection unit 31. And the alternative control apparatus 1 may repeat the operation | movement from step S201. Alternatively, the alternative control apparatus 1 may determine that a failure that is not a failure to be recovered by, for example, restarting has occurred in the failed device, and end the operation of FIG. Alternatively, the alternative control device 1 may end the operation of FIG. 12 after repeating the operations from step S201 to step S205 a predetermined number of times.

  When the failure detection unit 10 detects that the failure has been resolved (No in step S204), the connection control device 1 ends the operation of FIG.

  If the address assigned to the failed device is the address assigned to the alternative device when the failed device is detected during the operation in step S203, the connection control apparatus 1 ends the operation of FIG. 12 as it is. .

  Otherwise, the substitute instruction unit 12 may assign the address assigned to the substitute device when the failed device is detected to the failed device. And the connection control apparatus 1 complete | finishes the operation | movement of FIG. 12 as it is.

  Alternatively, the substitution instruction unit 12 may assign an address assigned to the substitution device when the faulty device is detected to the substitution device. In this case, the substitution instruction unit 12 further assigns the address assigned to the failed device to the failed device when the failed device is detected. And the connection control apparatus 1 complete | finishes the operation | movement of FIG. 12 as it is.

  The embodiment described above has an effect that the failed device can be operated again when the failure that has occurred in the device is a failure that is resolved by reset.

  The reason is that the reset unit 15 transmits a reset signal to the failed device. This is because when it is detected that the fault that has occurred in the faulty device has been resolved, the faulty device returns to the state connected to the signal source and the bus 2.

  Next, a third embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 13 is a block diagram illustrating an example of the configuration of the alternative control device 1B of the present embodiment.

  Referring to FIG. 13, the alternative control device 1 </ b> B according to the present embodiment is connected to a signal source through a signal connection unit 33 and is connected to a bus 2. A plurality of devices that return data based on a signal from a signal source, a failure detection unit that detects a failed device in which a failure has occurred, and a specific device other than the failed device among the plurality of devices, When an operation instruction is received, an alternative instruction unit 12 that transmits the alternative operation instruction to an alternative device that receives and executes an instruction for the failed device, and when a switching instruction is received, the alternative device that is connected to the failed device And a connection control unit 11 that transmits the switching instruction to the signal connection unit 33 that connects a signal source to the alternative device.

  The present embodiment described above has the same effect as the first effect of the first embodiment.

  The reason is the same as the first effect of the first embodiment.

  The alternative control device 1, the alternative control device 1A, and the alternative control device 1B are each realized by a computer and a program for controlling the computer, dedicated hardware, or a combination of a program for controlling the computer and the computer and dedicated hardware. be able to.

  FIG. 14 is a diagram illustrating an example of a configuration of a computer 1000 used to realize the alternative control device 1, the alternative control device 1A, and the alternative control device 1B. Referring to FIG. 14, a computer 1000 includes a processor 1001, a memory 1002, a storage device 1003, and an I / O (Input / Output) interface 1004. The computer 1000 can access the recording medium 1005. The memory 1002 and the storage device 1003 are storage devices such as a RAM (Random Access Memory) and a hard disk, for example. The recording medium 1005 is, for example, a storage device such as a RAM or a hard disk, a ROM (Read Only Memory), or a portable recording medium. The storage device 1003 may be the recording medium 1005. The processor 1001 can read and write data and programs from and to the memory 1002 and the storage device 1003. The processor 1001 can access, for example, the bus 2 via the I / O interface 1004. The processor 1001 can access the recording medium 1005. The recording medium 1005 stores a program that causes the computer 1000 to operate as the alternative control device 1, the alternative control device 1A, or the alternative control device 1B.

  The processor 1001 loads a program stored in the recording medium 1005 that causes the computer 1000 to operate as the alternative control device 1, the alternative control device 1A, or the alternative control device 1B to the memory 1002. Then, when the processor 1001 executes the program loaded in the memory 1002, the computer 1000 operates as the alternative control device 1, the alternative control device 1A, or the alternative control device 1B.

  Fault detection unit 10, connection control unit 11, substitution instruction unit 12, command transmission unit 13, reset unit 15, bus connection unit 31, bus connection unit 31A, bus connection unit 31B, signal connection unit 33, signal connection unit 33A, signal The connection unit 33B can be realized by, for example, a dedicated program for realizing the function of each unit read from the recording medium 1005 that stores the program into the memory 1002, and the processor 1001 that executes the program. The instruction storage unit 14 can be realized by a memory 1002 included in the computer or a storage device 1003 such as a hard disk device. Alternatively, the failure detection unit 10, the connection control unit 11, the substitution instruction unit 12, the command transmission unit 13, the command storage unit 14, the reset unit 15, the bus connection unit 31, the bus connection unit 31A, the bus connection unit 31B, and the signal connection unit 33. In addition, part or all of the signal connection unit 33A and the signal connection unit 33B can be realized by a dedicated circuit that realizes the function of each unit.

  The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

1, 1A, 1B Alternative control device 2 Bus 4 Control device 10 Failure detection unit 11 Connection control unit 12 Alternative instruction unit 13 Command transmission unit 14 Command storage unit 15 Reset unit 31, 31A, 31B Bus connection unit 32A, 32B Device 33, 33A, 33B Signal connection unit 34A, 34B Signal source 100, 100A Information processing system 1000 Computer 1001 Processor 1002 Memory 1003 Storage device 1004 I / O interface 1005 Recording medium

Claims (10)

A failure occurs from a plurality of devices connected to the signal source through the signal connection means and connected to the bus, and returning data based on the signal from the signal source to the received command via the bus. Fault detection means for detecting a faulty device,
Alternative instruction means for transmitting the alternative operation instruction to an alternative device that is a specific device other than the failed device among the plurality of devices and that receives and executes an instruction for the failed device when receiving the alternative operation instruction When,
When receiving a switching instruction, connection control means for transmitting the switching instruction to the signal connection means for connecting the signal source connected to the failed device to the alternative device; and
Alternative control unit including. The instruction for which the response is not returned is stored in an instruction storage unit, and when the failure device is detected and the operation change instruction is transmitted and the switching instruction is transmitted, the failure stored in the instruction storage unit is stored. Command transmitting means for transmitting the command to the device via the bus;
The instruction storage means;
The alternative control device according to claim 1, comprising: The plurality of devices are connected to the bus via bus connection means, and to different signal sources via the signal connection means,
The connection control means further transmits the disconnection instruction when the faulty device is detected to the bus connection means that disconnects the connection between the bus and the faulty device upon receiving the disconnection instruction. ,
The signal connection means, upon receiving the switching instruction, further connects a signal source connected to the alternative device before receiving the switching instruction to the faulty device,
The alternative control device includes reset means for transmitting the reset signal to the faulty device that returns to an initial state upon receiving a reset signal,
The failure detection means further detects the cancellation of the failure in the failed device when the reset signal is transmitted,
When the replacement instruction is detected, the replacement instruction unit transmits the replacement operation instruction to the failed device that operates as the replacement device when receiving the replacement operation instruction.
The connection control means transmits the connection instruction to the bus connection means for connecting the failed device to the bus when a connection instruction is received when the failure of the failed device is resolved. Alternative control device as described in 1. The plurality of devices;
A control device for transmitting the command and receiving the data;
An information processing system comprising: the alternative control device according to claim 1. A failure occurs from a plurality of devices connected to the signal source through the signal connection means and connected to the bus, and returning data based on the signal from the signal source to the received command via the bus. Detect the faulty device
When the alternative operation instruction is received from a specific device other than the failed device among the plurality of devices, the alternative operation instruction is transmitted to an alternative device that receives and executes an instruction for the failed device;
When the switching instruction is received, the switching instruction is transmitted to the signal connection unit that connects the signal source connected to the failed device to the alternative device.
Alternative control method. The instruction for which the response is not returned is stored in an instruction storage unit, and when the failure device is detected and the operation change instruction is transmitted and the switching instruction is transmitted, the failure stored in the instruction storage unit is stored. Sending the instructions to the device via the bus;
The alternative control method according to claim 5. Connecting the plurality of devices to the bus via a bus connection means and to different signal sources via the signal connection means;
Further, when the disconnection instruction is received, the disconnection instruction is transmitted to the bus connection unit that disconnects the connection between the bus and the faulty device when the faulty device is detected,
When the switching instruction is received, the signal source that was connected to the alternative device before receiving the switching instruction is further connected to the failed device,
When the reset signal is received, the reset signal returns to the initial state, and the reset signal is transmitted.
Further, when the reset signal is transmitted, detection of the failure in the failed device is detected,
When it is detected that a failure has been resolved in the failed device, the substitute operation instruction is transmitted to the failed device operating as the substitute device when the substitute operation instruction is received;
7. The alternative control method according to claim 5, wherein, when the elimination of the failure in the failed device is detected, when the connection instruction is received, the connection instruction is transmitted to the bus connection unit that connects the failed device to the bus. 8. . Computer
A failure occurs from a plurality of devices connected to the signal source through the signal connection means and connected to the bus, and returning data based on the signal from the signal source to the received command via the bus. Fault detection means for detecting a faulty device,
Alternative instruction means for transmitting the alternative operation instruction to an alternative device that is a specific device other than the failed device among the plurality of devices and that receives and executes an instruction for the failed device when receiving the alternative operation instruction When,
When receiving a switching instruction, connection control means for transmitting the switching instruction to the signal connection means for connecting the signal source connected to the failed device to the alternative device; and
Alternative control program to be operated. Computer
The instruction for which the response is not returned is stored in an instruction storage unit, and when the failure device is detected and the operation change instruction is transmitted and the switching instruction is transmitted, the failure stored in the instruction storage unit is stored. Command transmitting means for transmitting the command to the device via the bus;
The instruction storage means;
The alternative control program according to claim 8, which is operated as described above. Computer
The fault detection means for detecting the faulty device from the plurality of devices connected to the bus via the bus connection means and to different signal sources via the signal connection means;
Further, the connection control means for transmitting the disconnection instruction when the faulty device is detected to the bus connection means for disconnecting the connection between the bus and the faulty device when receiving the disconnection instruction;
When receiving the switching instruction, the signal connection means for connecting the signal source connected to the alternative device before receiving the switching instruction to the faulty device;
A reset means for transmitting the reset signal to the faulty device that returns to an initial state upon receiving a reset signal;
Further, when the reset signal is transmitted, the failure detection means for detecting the resolution of the failure in the failed device;
The replacement instruction means for transmitting the replacement operation instruction to the failure device operating as the replacement device when the replacement operation instruction is received when the failure of the failure device is detected;
The connection control means for transmitting the connection instruction to the bus connection means for connecting the failed device to the bus when receiving a connection instruction when the failure of the failed device is detected;
The alternative control program according to claim 8 or 9, which is operated as described above.

Images