Control device and control program

Abstract

To allow its own device to be continuously used even when an error occurs in data communication through a communication interface that connects between two control boards.SOLUTION: A control device includes a first control board and a second control board that each have a processor and a communication interface and are connected through the communication interfaces. When detecting occurrence of an error in data communication by the communication interfaces, at least one of the processors of the first and second control boards uses an unused signal line among signal lines provided in the communication interfaces and performs the data communication.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device and a control program. [Background technology]

[0002] Patent document 1 discloses an image forming apparatus comprising: a code storage device which is a processing device that stores boot code; a code execution device which is a processing device that executes booting based on the boot code obtained from the code storage device; communication means that connects the code storage device and the code execution device; and high-speed communication means that connects the code storage device and the code execution device and has a communication speed faster than that of the communication means, wherein the code storage device comprises code storage means that stores a high-speed utilization code which is the boot code that enables the code execution device to use the high-speed communication means, and a high-speed route code which is the boot code that is sent to the code execution device via the high-speed communication means, and code transmission means that transmits the high-speed utilization code to the code execution device via the communication means and then transmits the high-speed route code to the code execution device via the high-speed communication means.

[0003] Patent Document 2 discloses a distributed control type image forming apparatus that includes a main control means for controlling the entire device and an operation unit control means for controlling key input and display on the operation unit, and that is characterized in that the main control means and the operation unit control means are connected by both an asynchronous serial communication line and a clock synchronous serial communication line that allows faster communication than communication via the asynchronous communication line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-15812 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-215914 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a control device and a control program that can continue to use the device even if an error occurs in data communication via a communication interface connecting two control boards. [Means for solving the problem]

[0006] The control device of the first aspect includes a first control board and a second control board, each having a processor and a communication interface, and connected via the communication interface, and when at least one of the processors of the first control board and the second control board detects an error in data communication via the communication interface, it performs the data communication using an unused signal line among the signal lines provided in the communication interface.

[0007] A control device according to a second aspect is the control device according to the first aspect, wherein the unused signal lines are two signal lines for controlling connection and disconnection of the communication interface while the power is on.

[0008] A control device according to a third aspect is the control device according to the second aspect, wherein the communication interface is PCIe, and the two signal lines are two signal lines for a PRSNT1 signal and a PRSNT2 signal defined in the PCIe standard.

[0009] A control device according to a fourth aspect is the control device according to the first aspect, wherein the unused signal lines are two signal lines for controlling start-up and resetting of the first control board or the second control board.

[0010] A control device according to a fifth aspect is the control device according to the fourth aspect, wherein the communication interface is PCIe, and the two signal lines are two signal lines for a WAKE signal and a PERST signal defined in the PCIe standard.

[0011] A control device according to a sixth aspect is the control device according to any one of the second to fifth aspects, wherein the processor executes the data communication by serial communication.

[0012] A control device according to a seventh aspect is the control device according to the sixth aspect, wherein the serial communication is UART communication or I2C communication.

[0013] A control device according to an eighth aspect is the control device according to the first aspect, wherein the unused signal lines are four signal lines including two signal lines for controlling the connection and disconnection of the communication interface while the power is on, and two signal lines for controlling the startup and reset of the first control board or the second control board, and the data communication is performed using the four signal lines as four signal lines for an SCLK signal, a SIMO signal, a SOMI signal, and an SS signal of the SPI standard.

[0014] A control device according to a ninth aspect is the control device according to the eighth aspect, wherein the communication interface is PCIe, and the four signal lines are four signal lines for a PRSNT1 signal, a PRSNT2 signal, a WAKE signal, and a PERST signal defined in the PCIe standard.

[0015] A control device according to a tenth aspect is a control device according to any one of the first to ninth aspects, wherein the processor executes service processing that can be executed in a limited operation mode when the data communication can be executed using the unused signal line.

[0016] A control device according to an eleventh aspect is the control device according to the tenth aspect, wherein the processor causes a display unit to display a list of service processes that can be executed in the limited operation mode.

[0017] A control program according to a twelfth aspect is a control program for a control device including a first control board and a second control board, each of which has a processor and a communication interface and is connected via the communication interface, wherein at least one of the processors of the first control board and the second control board causes a computer to execute the data communication using an unused signal line among the signal lines provided in the communication interface when it detects an error in data communication via the communication interface. [Effects of the Invention]

[0018] According to the first and twelfth aspects, even if an error occurs in data communication via a communication interface connecting two control boards, the device itself can be continuously used.

[0019] According to the second aspect, there is an effect that the two signal lines for controlling the connection and disconnection of the communication interface while the power is on can be effectively utilized when an error occurs in data communication.

[0020] According to the third aspect, there is an effect that the two signal lines for the PRSNT1 signal and the PRSNT2 signal defined in the PCIe standard can be effectively utilized when an error occurs in data communication.

[0021] According to the fourth aspect, there is an effect that the two signal lines for controlling the start-up and resetting of the first control board or the second control board can be effectively utilized when an error occurs in data communication.

[0022] According to the fifth aspect, there is an effect that the two signal lines for the WAKE signal and the PERST signal defined in the PCIe standard can be effectively utilized when an error occurs in data communication.

[0023] According to the sixth aspect, there is an effect that data communication can be performed even when there are few unused signal lines, compared to when parallel communication is performed.

[0024] According to the seventh aspect, there is an effect that data communication with higher versatility can be performed compared to when serial communication other than UART communication and I2C communication is performed.

[0025] According to the eighth aspect, the unused signal lines have the advantage that four signal lines, including two signal lines for controlling the connection and disconnection of the communication interface while the power is on, and two signal lines for controlling the startup and reset of the first control board or the second control board, can be effectively utilized in the event of an error in data communication.

[0026] According to the ninth aspect, it is possible to effectively utilize the four signal lines of the PRSNT1 signal, the PRSNT2 signal, the WAKE signal, and the PERST signal defined in the PCIe standard when an error occurs in data communication.

[0027] According to the tenth aspect, even if an error occurs in data communication, it is possible to continue operation in the limited operation mode.

[0028] According to the eleventh aspect, it is possible to easily grasp executable service processes when an error occurs in data communication. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 2 is a block diagram showing an example of an electrical configuration of the image forming apparatus. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a control device. [Figure 3] 10 is a flowchart showing an example of a processing flow according to a control program. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an example of an embodiment for carrying out the technology of the present disclosure will be described in detail with reference to the drawings.

[0031] FIG. 1 is a block diagram showing an example of the electrical configuration of an image forming apparatus 10 according to the first embodiment.

[0032] As shown in FIG. 1, the image forming apparatus 10 according to this embodiment includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a non-volatile memory 14, an input / output interface (I / O) 15, an AISC (Application Specific Integrated Circuit) 16, a communication interface (I / F) 17, a memory unit 18, a display unit 19, an operation unit 20, a communication unit 21, a document reading unit 22, and an image forming unit 23.

[0033] The CPU 11, ROM 12, RAM 13, non-volatile memory 14, and I / O 15 are connected to each other via a bus. Functional units including a storage unit 18, a display unit 19, an operation unit 20, a communication unit 21, a document reading unit 22, and an image forming unit 23 are connected to the I / O 15. The storage unit 18, the display unit 19, the operation unit 20, and the communication unit 21 are capable of communicating with the CPU 11 via the I / O 15. The document reading unit 22 and the image forming unit 23 are connected to the ASIC 16. The ASIC 16 is capable of communicating with the CPU 11 via a communication I / F 17.

[0034] The control device 40 is configured with the CPU 11, ROM 12, RAM 13, nonvolatile memory 14, I / O 15, ASIC 16, and communication I / F 17. The control device 40 may be configured as a sub-controller that controls part of the operation of the image forming apparatus 10, or as part of a main control unit that controls the overall operation of the image forming apparatus 10. For example, integrated circuits such as LSI (Large Scale Integration) or IC (Integrated Circuit) chip sets are used for some or all of the blocks of the control device 40. Individual circuits may be used for each of the above blocks, or a circuit in which some or all of the blocks are integrated may be used. The above blocks may be provided integrally, or some of the blocks may be provided separately. Furthermore, parts of each of the above blocks may be provided separately. The integration of control is not limited to LSI, and a dedicated circuit or a general-purpose processor may also be used.

[0035] The nonvolatile memory 14 is configured as a rewritable memory, and stores a control program 14A of the control device 40 according to this embodiment. The control program 14A may be pre-installed in the control device 40, for example. The control program 14A may also be provided by a nonvolatile storage medium such as a CD-ROM (Compact Disc Read Only Memory), or may be provided by being downloaded via a network.

[0036] For example, a hard disk drive (HDD), a solid state drive (SSD), a flash memory, etc. is used as the storage unit 18. The storage unit 18 stores programs, data, etc. related to various functions of the image forming apparatus 10.

[0037] For example, a liquid crystal display (LCD), an organic electroluminescence (EL) display, etc. may be used for the display unit 19. The display unit 19 may be integrally provided with a touch panel.

[0038] The operation unit 20 is provided with various operation keys such as a numeric keypad and a start key. The display unit 19 and the operation unit 20 function as an operation panel and receive various instructions from a user of the image forming apparatus 10. These various instructions include, for example, an instruction to start reading a document or an instruction to start copying a document. The display unit 19 displays various information such as the results of processing executed in response to instructions received from the user and notifications regarding the processing.

[0039] The communication unit 21 is connected to a network such as the Internet, a local area network (LAN), or a wide area network (WAN), and is capable of communicating with external devices such as personal computers (PCs) via the network.

[0040] The document reading unit 22 takes in documents placed on a paper feed tray of an automatic document feeder (not shown) provided on the top of the image forming apparatus 10, one by one, and optically reads the taken-in documents to obtain image information. Alternatively, the document reading unit 22 optically reads a document placed on a document tray such as a platen glass to obtain image information.

[0041] The image forming unit 23 forms an image on a sheet of paper, which is an example of a recording medium, based on the image information obtained by reading by the document reading unit 22. Note that, although the following description will be given using an electrophotographic method as an example of a method for forming an image, other methods such as an inkjet method may also be used.

[0042] When the image formation method is electrophotography, the image forming unit 23 includes a photosensitive drum, a charging device, an exposure device, a developing device, a transfer device, and a fixing device. The charging device applies a voltage to the photosensitive drum to charge the surface of the photosensitive drum. The exposure device forms an electrostatic latent image on the photosensitive drum by exposing the photosensitive drum, which has been charged by the charging device, to light corresponding to image information. The developing device develops the electrostatic latent image formed on the photosensitive drum with toner to form a toner image on the photosensitive drum. The transfer device transfers the toner image formed on the photosensitive drum to paper. The fixing device fixes the toner image transferred to the paper by applying heat and pressure.

[0043] FIG. 2 is a block diagram showing an example of the configuration of the control device 40 according to this embodiment.

[0044] 2, the control device 40 according to this embodiment includes a controller board 50 and an engine control board 60. The engine unit 70 includes the engine control board 60, a document reading unit 22, and an image forming unit 23. The controller board 50 is an example of a first control board, and the engine control board 60 is an example of a second control board. Note that the ROM 12, RAM 13, nonvolatile memory 14, and I / O 15 are included in the controller board 50, but will not be described here for the sake of simplicity.

[0045] The controller board 50 includes a CPU 11 and a communication I / F 17A. The CPU 11 is an example of a processor of the first control board, and controls the overall operation of the image forming apparatus 10.

[0046] The engine control board 60 includes an ASIC 16 and a communication I / F 17B. The ASIC 16 is an example of a processor of the second control board, and controls specific processing executed by the image forming apparatus 10, which in this embodiment is image processing. The document reading unit 22 inputs image data to the ASIC 16, and the image forming unit 23 outputs the image data received from the ASIC 16 after image processing. When there is no need to distinguish between the communication I / Fs 17A and 17B, they are simply referred to as the communication I / F 17.

[0047] The controller board 50 and the engine control board 60 are separate boards, and are connected to each other via a communication I / F 17, thereby enabling communication between the CPU 11 and the ASIC 16. In this embodiment, as an example, PCIe (Peripheral Component Interconnect-Express) is applied to the communication I / F 17.

[0048] The reason why the controller board 50 and the engine control board 60 are separate boards is that the controller board 50 and the engine control board 60 may be designed by different people. In this case, data communication errors may be more likely to occur than when the CPU 11 and ASIC 16 are provided on a single board and designed by a single designer. In this case, the image forming apparatus 10 cannot be used until the data communication error is resolved.

[0049] Therefore, the CPU 11 of the control device 40 according to this embodiment writes the control program 14A stored in the nonvolatile memory 14 to the RAM 13 and executes it. When an error is detected in data communication via the communication I / F 17 connecting the controller board 50 and the engine control board 60, the CPU 11 executes data communication using an unused signal line among the signal lines provided in the communication I / F 17. An unused signal line is a signal line that is not used during normal operation when no error occurs in data communication. In this way, the unused signal line during normal operation is used as a signal line for backup communication if an error occurs in data communication. This allows the image forming device 10 to be used continuously until repairs, such as a board replacement, are performed.

[0050] Here, examples of unused signal lines among those included in the communication I / F 17 include two signal lines for controlling connection and disconnection of the communication I / Fs 17A and 17B while the power is on, i.e., two signal lines for hot plugging. The controller board 50 and the engine control board 60 remain connected by the communication I / F 17 during manufacturing and are never disconnected during operation of the image forming apparatus 10, so the two signal lines for hot plugging are unused. Specifically, because the communication I / F 17 is a PCIe, the two signal lines for the PRSNT1 signal and the PRSNT2 signal defined by the PCIe standard are unused signal lines. In this embodiment, a case will be described in which, when an error occurs in data communication, backup communication is performed using the two unused signal lines for the PRSNT1 signal and the PRSNT2 signal.

[0051] Another example of unused signal lines is two signal lines for controlling the startup and reset of the controller board 50 and the engine control board 60. As described above, the controller board 50 and the engine control board 60 remain connected by the communication I / F 17 at the time of manufacture and are not disconnected during operation of the image forming apparatus 10, so the two signal lines for controlling the startup and reset of the controller board 50 and the engine control board 60 are unused. Specifically, because the communication I / F 17 is PCIe, the two signal lines for the WAKE signal and the PERST signal defined by the PCIe standard are unused signal lines.

[0052] The data communication method using the two unused signal lines may be, for example, serial communication. Specifically, UART (Universal Asynchronous Receiver / Transmitter) communication or I2C (Inter-Integrated Circuit) communication may be used, but is not limited to these. Note that because it is serial communication, the data transfer speed is slower than normal bus communication according to the PCIe standard.

[0053] In addition, the unused signal lines are four signal lines including two signal lines for controlling the connection and disconnection of the communication I / F 17 while the power is on, and two signal lines for controlling the start and reset of the controller board 50 and the engine control board 60, and these four signal lines may be used as four signal lines for the SCLK signal, SIMO signal, SOMI signal, and SS signal of the SPI (Serial Peripheral Interface) standard to perform data communication.

[0054] Specifically, since the communication I / F 17 is PCIe, the four signal lines of the PRSNT1 signal, the PRSNT2 signal, the WAKE signal, and the PERST signal defined in the PCIe standard may be used as the four signal lines of the SCLK signal, the SIMO signal, the SOMI signal, and the SS signal of the SPI standard to perform data communication.

[0055] Although the CPU 11 detects the occurrence of an error in the above example, the ASIC 16 may also detect the occurrence of an error. That is, a control program may be stored in a data-rewritable nonvolatile memory of the engine control board 60 on the ASIC 16 side, and the ASIC 16 may execute the control program. In this case, similar to the CPU 11, when the ASIC 16 detects an error in data communication via the communication I / F 17 connecting the controller board 50 and the engine control board 60 by executing the control program, the ASIC 16 executes data communication using an unused signal line among the signal lines provided in the communication I / F 17. Also, both the CPU 11 and the ASIC 16 may be capable of executing the control program.

[0056] Next, the control process executed by the CPU 11 of the control device 40 according to this embodiment will be described with reference to FIG.

[0057] 3 is a flowchart showing an example of the flow of processing by the control program according to this embodiment. First, when the power supply of the control device 40 is turned on, the control program is started by the CPU 11, and the following steps are executed. Note that, although the case where the CPU 11 executes the control program will be described here, the same applies when the ASIC 16 executes the control program.

[0058] In step S100, the CPU 11 determines whether an error has occurred in data communication via the communication I / F 17 connecting the controller board 50 and the engine control board 60. Whether an error has occurred in data communication is determined, for example, by determining whether a response has been received from the ASIC 16 within a predetermined time period when data communication is performed in which data is sent to the ASIC 16 and a response from the ASIC 16 is required. In addition, if an error detection code is added to the data received from the ASIC 16, whether an error has occurred in data communication may be detected by determining whether an error has been detected in the data by the error detection code. Note that the method for determining whether an error has occurred is not limited to this.

[0059] If it is determined that an error has occurred, the process proceeds to step S102, and if an error has not been detected, it continues to determine whether an error has occurred in the data communication.

[0060] In step S102, the CPU 11 generates log information. The log information includes, for example, information indicating the situation when an error occurs in data communication, such as the content of the process being executed by the CPU 11, and the like.

[0061] In step S104, the CPU 11 determines whether backup communication using unused signal lines is possible. Specifically, a procedure for performing backup communication is determined in advance, and a connection confirmation signal for confirming connection is transmitted to the ASIC 16 via serial communication such as UART using two unused signal lines for the PRSNT1 signal and the PRSNT2 signal. When the ASIC 16 receives the connection confirmation signal, it transmits a response signal to the CPU 11. When the CPU 11 receives the response signal, it determines that backup communication is possible, and when the CPU 11 does not receive the response signal within a predetermined time, it determines that backup communication is impossible.

[0062] If the determination in step S104 is affirmative, the process proceeds to step S106, and if the determination in step S104 is negative, the process proceeds to step S114.

[0063] In step S106, the CPU 11 transmits the log information generated in step S102 by preliminary communication to the ASIC 16. This enables the ASIC 16 to grasp the situation when an error occurs on the CPU 11 side.

[0064] In step S108, the CPU 11 transitions to a limited operation mode and executes processing that can only be executed in the limited operation mode. Here, the limited operation mode is a mode in which only service processing that can be provided even with low-speed serial communication using two unused signal lines is executed.

[0065] In step S110, the CPU 11 displays on the display unit 19 that the device is operating in the limited operation mode and a list of service processes that can be executed in the limited operation mode.

[0066] In step S112, the CPU 11 transmits repair request information requesting repair to a terminal device of an external repair company via a communication line connected to the communication unit 21. Information instructing the user to call a repair company, such as a message such as "The circuit board needs to be replaced, so please call a repair technician!", may be displayed on the display unit 19.

[0067] On the other hand, if the determination in step S104 is negative, the operation is stopped because the preparatory communication cannot be performed and no service can be provided. Note that a message to the effect that the service cannot be provided may be displayed on the display unit 16.

[0068] As described above, according to this embodiment, when an error is detected in data communication via the communication I / F 17 connecting the controller board 50 and the engine control board 60, data communication is performed using an unused signal line among the signal lines provided in the communication I / F 17. This allows the image forming apparatus 10 to be used continuously until repairs such as board replacement are performed.

[0069] 3 may be executed by the ASIC 16. In this case, in the description of the processing in FIG. 3, the CPU 11 may be replaced with the ASIC 16, and the ASIC 16 may be replaced with the CPU 11. However, in the processing of step S110, since the display unit 16 is provided on the controller board 50 side, the ASIC 16 requests the CPU 11 to execute the processing of step S110 by preliminary communication. Similarly, in the processing of step S112, since the communication unit 21 is provided on the controller board 50 side, the ASIC 16 requests the CPU 11 to execute the processing of step S112 by preliminary communication.

[0070] In each of the above embodiments, the control device according to the embodiment is described as being applied to an image forming device, but it goes without saying that the application is not limited to an image forming device and can be applied to other information processing devices such as a server computer, a personal computer, etc.

[0071] In each of the above embodiments, the term "processor" refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0072] Furthermore, the operations of the processor in each of the above embodiments may not only be performed by a single processor, but may also be performed by multiple processors located at physically separate locations working together. Furthermore, the order of the operations of the processor is not limited to the order described in each of the above embodiments, and may be changed as appropriate.

[0073] The above describes the control device according to the embodiment and the image forming apparatus equipped with the control device. The embodiment may be in the form of a program for causing a computer to execute the functions of the control device. The embodiment may be in the form of a non-transitory storage medium that stores the program and is readable by a computer.

[0074] Furthermore, the configuration of the control device described in the above embodiment is merely an example, and may be changed depending on the situation without departing from the spirit of the invention.

[0075] Furthermore, the processing flow of the program described in the above embodiment is also an example, and unnecessary steps may be deleted, new steps may be added, or the processing order may be rearranged within the scope of the main idea.

[0076] In the above embodiment, the processing according to the embodiment is realized by a software configuration using a computer by executing a program, but the present invention is not limited to this. The embodiment may be realized by, for example, a hardware configuration or a combination of a hardware configuration and a software configuration. [Explanation of symbols]

[0077] 10 Image forming device 14 Non-volatile memory 14A Control Program 16 ASIC 17 Communication I / F 18 Memory section 19 Display section 20 Control section 21 Communications Department 22 Document reading unit 23 Image forming unit 40 Control device 50 Controller board 60 Engine control board

Claims

1. a first control board and a second control board each having a processor and a communication interface and connected via the communication interface; At least one of the processors of the first control board and the second control board When an error is detected in data communication by the communication interface, the data communication is performed using an unused signal line that is not used during normal operation when no error occurs in the data communication, among signal lines provided in the communication interface. Control device.

2. The unused signal lines are two signal lines for controlling connection and disconnection of the communication interface while the power is on. The control device according to claim 1 .

3. The communication interface is PCIe, and the two signal lines are two signal lines for a PRSNT1 signal and a PRSNT2 signal defined in the PCIe standard. The control device according to claim 2.

4. The unused signal lines are two signal lines for controlling the start and reset of the first control board or the second control board. The control device according to claim 1 .

5. The communication interface is PCIe, and the two signal lines are two signal lines for a WAKE signal and a PERST signal defined in the PCIe standard. The control device according to claim 4.

6. The processor executes the data communication by serial communication. The control device according to any one of claims 2 to 5.

7. The serial communication is UART communication or I2C communication. The control device according to claim 6.

8. the unused signal lines are four signal lines including two signal lines for controlling connection and disconnection of the communication interface while the power is on, and two signal lines for controlling start-up and reset of the first control board or the second control board, The four signal lines are used as four signal lines for the SCLK signal, the SIMO signal, the SOMI signal, and the SS signal of the SPI standard, and the data communication is performed. The control device according to claim 1 .

9. The communication interface is PCIe, and the four signal lines are four signal lines for a PRSNT1 signal, a PRSNT2 signal, a WAKE signal, and a PERST signal, which are defined in the PCIe standard. The control device according to claim 8.

10. The processor: If the data communication can be performed using the unused signal line, a service process that can be performed in a limited operation mode is performed. The control device according to any one of claims 1 to 9.

11. The processor: A list of service processes that can be executed in the limited operation mode is displayed on a display unit. The control device according to claim 10.

12. A control program for a control device including a first control board and a second control board, each of which has a processor and a communication interface and is connected via the communication interface, At least one of the processors of the first control board and the second control board, When an error is detected in data communication by the communication interface, the data communication is performed using an unused signal line that is not used during normal operation when no error occurs in the data communication, among signal lines provided in the communication interface. A control program for executing a process including the above.

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