A watchdog biting and cutting machine circuit for multi-machine cold backup system

Abstract

This invention discloses a watchdog switching circuit for a multi-machine cold backup system. The output of the watchdog reset circuit is connected sequentially to the input of the switching combinational logic control circuit and the watchdog bite count circuit. The output of the watchdog bite count circuit is connected to the input of a monostable integrated circuit. The output of the monostable integrated circuit is connected to the switching combinational logic control circuit. The switching combinational logic control circuit is connected to a command pulse output circuit. By adding a monostable integrated circuit, the high-level signal is converted into a high-pulse signal. The input of the command pulse output circuit is also a high pulse. The transistor in the command pulse output circuit will conduct during the pulse's validity period, thereby ensuring the validity of the standby power-on command. This optimizes the process of ending the standby power-on command through multiple watchdog bite signals, avoids the problem of abnormally constant enable of the watchdog switching signal under certain conditions, and improves the reliability and security of the computer redundancy switching strategy.

Description

Technical Field

[0001] The invention belongs to the technical field of watchdog circuits and relates to a watchdog biting machine circuit for a multi-machine cold backup system. Background Art

[0002] At present, the commonly used watchdog switching strategy in multi-machine cold backup satellite computers is to reset by one dog bite, and then power on the single machine of the cold backup after multiple dog bites to complete the switching of working control rights. The power-on instruction of the cold backup machine is usually generated by the combinational logic of the multi-bit output signal of the shift register. Since the watchdog needs to generate a pulse signal as the power-on instruction of the cold backup machine after biting, if the instruction abnormally outputs a level signal under certain specific conditions, the power-on instruction will become a normal enable signal. In this state, the single machine cannot be powered off, resulting in the problem of abnormal switchable signal during the watchdog biting switching process. Summary of the invention

[0003] In view of the problem of abnormal cutting signal in the watchdog cutting process in the prior art, the present invention provides a watchdog cutting circuit for a multi-machine cold backup system, optimizes the output mode of the watchdog cutting signal of the onboard computer, and solves the problem that the cutting signal may be always effective during the watchdog cutting process.

[0004] The present invention is achieved through the following technical solutions:

[0005] A watchdog biting and cutting machine circuit for a multi-machine cold backup system, comprising a watchdog reset circuit, a dog biting times counting circuit, a monostable integrated circuit, a cutting machine combination logic control circuit and a command pulse output circuit;

[0006] The output end of the dog bite count circuit is connected to the input end of the monostable integrated circuit to convert the high level signal into a high pulse signal.

[0007] The output end of the monostable integrated circuit is connected to the power-off combination logic control circuit, which is used to generate a control signal for outputting a power-off instruction after performing a logic combination on the output high pulse signal;

[0008] The machine cutting combination logic control circuit is connected to the command pulse output circuit to generate a standby machine power-on command signal;

[0009] The output end of the watchdog reset circuit is connected to the cutter combination logic control circuit and the dog bite times counting circuit in sequence, and is used to clear the watchdog signal of the watchdog dog bite cutter circuit.

[0010] Preferably, the CLK terminal of the dog bite count circuit is connected to the watchdog dog bite signal output terminal, and is used to record the number of periodic pulses output by the watchdog count circuit, and output a dog bite cutting instruction after multiple dog bites occur in a single machine.

[0011] Preferably, the cutting machine combination logic control circuit includes a first AND gate circuit, a second AND gate circuit and a NOT gate circuit;

[0012] The first input end of the first AND gate circuit is connected to the output end of the monostable integrated circuit, and the second input end of the first AND gate circuit is connected to the watchdog reset circuit; the output end of the first AND gate circuit is connected to the input end of the command pulse output circuit;

[0013] The input end of the NOT gate circuit is connected to the output end of the instruction pulse output circuit; the output end of the NOT gate circuit is connected to the second input end of the second AND gate; the first input end of the second AND gate is connected to the watchdog reset circuit, and the output end of the second AND gate is connected to the CLR end of the dog bite count circuit.

[0014] Preferably, the monostable integrated circuit is connected to a first resistor R1 and a capacitor C; the RX-CX terminals of the monostable integrated circuit are respectively connected to the first connection terminal of the capacitor C and the first resistor R1, and the CX terminal and A_ terminal of the monostable integrated circuit are both connected to the second connection terminal of the capacitor C.

[0015] Preferably, one end of the first resistor R1 is respectively connected to the VCC terminal and the power supply terminal of the monostable integrated circuit.

[0016] Preferably, the CLR terminal of the monostable integrated circuit is connected to a second resistor R2.

[0017] Preferably, the instruction pulse output circuit adopts a Darlington tube circuit, and the model of the Darlington tube circuit is KG25A.

[0018] Preferably, the QB terminal of the dog bite count circuit is connected to the B terminal of the monostable integrated circuit.

[0019] Preferably, the monostable integrated circuit adopts a monostable trigger of model 54HC123.

[0020] Preferably, the dog bite count circuit uses a 54HC164 chip.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] The watchdog bite cutter circuit for a multi-machine cold standby system provided by the present invention optimizes the design of the watchdog bite cutter circuit for the multi-machine cold standby system, converts a high-level signal into a high-pulse signal by adding a monostable integrated circuit, and uses a monostable trigger to generate a power-on command pulse. When the watchdog bites for the second time, the second-level output of the dog bite count circuit changes from a low level to a high level, triggering the monostable integrated circuit to output a high pulse of a fixed width, and the input end of the command pulse output circuit is also a high pulse. The triode in the command pulse output circuit will be turned on during the effective period of the pulse, so that the standby machine power-on command is effective, and the optimization is carried out. The design of terminating the standby machine power-on instruction through multiple dog bite signals avoids the problem that the watchdog's multiple dog bite signals are not generated, resulting in the input signal of the instruction pulse output circuit being always high, thereby making the output standby machine power-on instruction always valid. The output method of the onboard computer watchdog dog bite cutting machine signal is optimized, which solves the problem that the cutting machine signal is always valid during the watchdog dog bite cutting machine process, avoids the risk of the standby machine being unable to be powered off after the product watchdog abnormality is powered on, improves the reliability and safety of the system fault tolerance, and can be applied to aerospace, aviation, military, civil and other fields, with high promotion and application value.

[0023] Furthermore, the monostable integrated circuit of the present invention adopts a 54HC123 monostable trigger to achieve fixed output of pulse instructions, avoiding the problem of abnormal constant enabling of the watchdog switching signal under specific conditions and the risk of the backup machine being unable to shut down, thereby improving the reliability and safety of the computer redundant switching strategy.

[0024] Furthermore, resistors and capacitors are arranged on the monostable integrated circuit of the present invention, and the high level output by the dog bite count circuit is converted into a high pulse in the monostable integrated circuit. The pulse width is adjusted by the resistor and the capacitor, so that the transistor in the command pulse output circuit can be effectively turned on during the pulse validity period, and the standby machine power-on command is always valid, further optimizing the design of terminating the standby machine power-on command by multiple dog bite signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a design diagram of a traditional watchdog cutting machine circuit in the prior art;

[0026] Figure 2 It is a timing diagram of a traditional watchdog switching circuit in the prior art;

[0027] Figure 3 This is a timing diagram of the watchdog cutting abnormality in the embodiment;

[0028] Figure 4 The block diagram of the watchdog switching circuit design of the dual-machine cold standby system of the present invention;

[0029] Figure 5 This is a timing diagram of the watchdog cutting circuit of the present invention;

[0030] Figure 6 It is a schematic diagram of a certain environmental control controller of a space station in the embodiment. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0032] A watchdog biting and cutting machine circuit for a multi-machine cold backup system, comprising a watchdog reset circuit, a dog biting times counting circuit, a monostable integrated circuit, a cutting machine combination logic control circuit and a command pulse output circuit;

[0033] The output end of the dog bite count circuit is connected to the input end of the monostable integrated circuit, and is used to convert a high-level signal into a high-pulse signal. The dog bite count circuit can record the number of periodic pulses output by the watchdog count circuit, that is, the number of watchdog dog bites. After multiple dog bites occur on a single machine, a dog bite machine cutting instruction can be output to power on another machine in cold backup.

[0034] The CLK terminal of the dog bite count circuit is connected to the watchdog dog bite signal output terminal, and is used to record the number of periodic pulses output by the watchdog count circuit. After multiple dog bites occur in a single machine, a dog bite cut-off instruction is output. The QB terminal of the dog bite count circuit is connected to the B terminal of the monostable integrated circuit. The dog bite count circuit adopts a 54HC164 chip.

[0035] The monostable integrated circuit adopts a monostable trigger of model 54HC123. The output end of the monostable integrated circuit is connected to the cutting combination logic control circuit, which is used to generate a control signal for the cutting command output after logically combining the output high pulse signal; the monostable trigger is used to generate a power-on command pulse, and when the watchdog bites the second-stage output of 54HC164 for the second time, it changes from a low level to a high level, triggering 54HC123 (monostable integrated circuit) to output a pulse of fixed width, and the pulse width is adjustable; the circuit output end QA-QH of the 54HC164 can output pulse signals of different periods according to different clock counts; the circuit input ends A and B of the 54HC164 are connected to a power supply, and the power supply in the circuit of the present invention adopts a power supply with a voltage of 5V;

[0036] The monostable integrated circuit is connected with a first resistor R1 and a capacitor C; the RX-CX terminals of the monostable integrated circuit are respectively connected to the first connection terminal of the capacitor C and the first resistor R1, and the CX terminal and the A_ terminal of the monostable integrated circuit are both connected to the second connection terminal of the capacitor C. One end of the first resistor R1 is respectively connected to the VCC terminal and the power supply terminal of the monostable integrated circuit. The monostable integrated circuit of the present invention is provided with a resistor and a capacitor, and the high level output by the dog bite count circuit is converted into a high pulse in the monostable integrated circuit. The pulse width is adjusted by the resistor and the capacitor, so that the triode in the instruction pulse output circuit can be effectively turned on during the pulse validity period, and the standby machine power-on instruction is always valid, which further optimizes the design of ending the standby machine power-on instruction by multiple dog bite signals.

[0037] The CLR terminal of the monostable integrated circuit is connected to a second resistor R2, one end of which is connected to a power supply terminal with a voltage of 5V; the GND terminal of the monostable integrated circuit is grounded; the second resistor R2 is a pull-up resistor of the clear terminal CLR of 54HC123, connected to a fixed level;

[0038] The cutting machine combination logic control circuit is connected to the instruction pulse output circuit, and is used to generate the standby machine power-on instruction signal; the cutting machine combination logic control circuit generates a control signal for the cutting machine instruction output after logically combining the level signal output by the counting circuit 54HC164. The cutting machine combination logic control circuit includes a first AND gate circuit, a second AND gate circuit and a NOT gate circuit; the first input end of the first AND gate circuit is connected to the output end of the monostable integrated circuit, and the second input end of the first AND gate circuit is connected to the watchdog reset circuit; the output end of the first AND gate circuit is connected to the input end of the instruction pulse output circuit; the input end of the NOT gate circuit is connected to the output end of the instruction pulse output circuit; the output end of the NOT gate circuit is connected to the second input end of the second AND gate; the first input end of the second AND gate is connected to the watchdog reset circuit, and the output end of the second AND gate is connected to the CLR end of the dog bite count circuit.

[0039] The output end of the watchdog reset circuit is connected to the cutting machine combination logic control circuit and the dog bite count circuit in sequence, and the power-on reset signal of the watchdog reset circuit is used to clear the watchdog signal of the watchdog dog bite cutting machine circuit. The watchdog reset circuit is to avoid abnormal product crashes. When the system software runs abnormally, a system reset signal is generated to return the hardware and software states of the product to the initial state and restart the operation.

[0040] The command pulse output circuit adopts a Darlington tube circuit, and the model of the Darlington tube circuit is KG25A. The command pulse output circuit is used to generate a drive signal for powering on another machine, and uses a Darlington tube KG25A in series. The Darlington tube circuit includes a first transistor and a second transistor, the base of the first transistor is connected to the output end of the first AND gate circuit, the collector of the first transistor is connected to the connection end of the standby machine power-on instruction at point B; the emitter of the first transistor is connected to the collector of the second transistor; the emitter of the second transistor is connected to the ground end; the base of the second transistor is connected to the output end of the first AND gate circuit;

[0041] The watchdog bite signal is a pulse signal generated by the existing circuit. If the watchdog bite occurs, a pulse will be generated. This pulse will cause the monostable trigger 54HC123 to output a pulse with a fixed width. This pulse width is set by R1 and C above.

[0042] The present invention will be described in detail below in conjunction with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0043] The following detailed descriptions are all descriptions of embodiments, and are intended to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention.

[0044] One of the preferred embodiments of the present invention:

[0045] The function of the watchdog bite cutter circuit is mainly to generate a backup machine power-on command signal when the product is running abnormally, power on the cold standby machine, and then hand over the control to the backup machine. The traditional on-board computer watchdog bite cutter circuit design consists of a watchdog reset circuit 54HC4060, a dog bite count circuit 54HC164, a cutter combination logic control circuit, and a command pulse output circuit. Figure 1 shown.

[0046] After the product is powered on, the output of 54HC164 is all low, the input of KG25A is invalid, and there is no output of the instruction. When an abnormality occurs during the operation of the product, when the watchdog bites for the first time, a system reset signal is generated, and at the same time, the count of 54HC164 is increased by 1, and QA outputs a high level; when the watchdog bites for the second time, the count of 54HC14 is increased by 1 again, and QB outputs a high level. At this time, the output of 54HC08 is high, then the output of KG25A is valid, the transistor is turned on, and the power-on instruction of the standby machine becomes low; when the watchdog bites for the third time, QC outputs a high level, and the signal becomes a low level after passing through 54HC14. At this time, the output of 54HC08 is low, then the output of KG25A is invalid, the transistor is not turned on, and the power-on instruction of the standby machine becomes high. Through the second and third dog bites, a low pulse will be generated at the output end of KG25A as the power-on instruction for the standby machine. The pulse width is the interval time between the two dog bites. The timing of the watchdog cutting machine is as follows Figure 2 As shown:

[0047] However, if an abnormality occurs and the watchdog fails to generate the third dog bite signal, the KG25A input signal is always high, the output standby power-on command is always valid, and the product will be at risk of not being able to shut down. Figure 3 As shown;

[0048] Therefore, the present invention optimizes the design for the possible risks of the traditional watchdog switch circuit, uses a monostable trigger to generate a power-on command pulse, and when the watchdog bites the second 54HC164, the second-stage output changes from a low level to a high level, triggering 54HC123 (monostable integrated circuit) to output a pulse with a fixed width, and the pulse width is adjustable. Figure 4 shown.

[0049] After the product is powered on, the output of 54HC164 is all low, the input of KG25A is invalid, and there is no output of the instruction. When an abnormality occurs during the operation of the product, when the watchdog bites for the first time, a system reset signal is generated, and at the same time, the 54HC164 count is increased by 1, and QA outputs a high level; when the watchdog bites for the second time, the 54HC14 count is increased by 1 again, and QB outputs a rising edge. At this time, the monostable trigger 54HC123 will output a high pulse, and the pulse width can be set by the resistor and capacitor R and C. The input of KG25A is also a high pulse, and the transistor will be turned on during the effective period of the pulse, so that the standby power-on instruction is valid. The design of ending the standby power-on instruction through the third dog bite signal is optimized to avoid the problem that the third watchdog dog bite signal is not generated, resulting in the KG25A input signal being always high, thereby making the output standby power-on instruction always valid. The optimized watchdog switching timing is as follows Figure 5 shown.

[0050] As one of the preferred embodiments of the present invention:

[0051] In my country's space station, a certain environmental control controller has a dual-machine cold standby system architecture, such as Figure 6 As shown in the figure, the product uses an optimized watchdog cutting machine circuit design to realize the dog bite cutting machine function in the event of a product failure. After the product is powered on, machine A is powered on and reset, and the application software is run normally and on duty, while machine B is in cold standby shutdown state. When machine A is abnormal, its watchdog of machine A is reset by dog ​​bite. At the second dog bite, the optimized watchdog circuit sends a secondary dog ​​bite cutting machine command pulse. The cutting machine command controls the relay of machine B after passing through the drive circuit, and powers on machine B. Even if there is no third dog bite, it does not affect the power-on and power-off work of machine B, avoiding the problem that the third dog bite signal of the watchdog is not generated, resulting in the input signal of the drive circuit being always high, thereby making the output of the power-on command of machine B always effective.

[0052] The above content is a further detailed description of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, they can also make several simple deductions or substitutions, which should be regarded as belonging to the protection scope of the present invention determined by the submitted claims.

Claims

1. A watchdog biting machine circuit for a multi-machine cold backup system, characterized in that: It includes a watchdog reset circuit, a dog bite count circuit, a monostable integrated circuit, a cutter combination logic control circuit and a command pulse output circuit; The output end of the watchdog reset circuit is connected to the input end of the cutter combination logic control circuit and the dog bite count circuit in sequence; the output end of the dog bite count circuit is connected to the input end of the monostable integrated circuit, which is used to convert the high level signal into a high pulse signal; The output end of the monostable integrated circuit is connected to the power-off combination logic control circuit, which is used to generate a control signal for outputting a power-off instruction after performing a logic combination on the output high pulse signal; The machine cutting combination logic control circuit is connected to the command pulse output circuit to generate a standby machine power-on command signal; The switch combination logic control circuit includes a first AND gate circuit, a second AND gate circuit and a NOT gate circuit; The first input end of the first AND gate circuit is connected to the output end of the monostable integrated circuit, and the second input end of the first AND gate circuit is connected to the watchdog reset circuit; the output end of the first AND gate circuit is connected to the input end of the command pulse output circuit; The input end of the NOT gate circuit is connected to the output end of the command pulse output circuit; the output end of the NOT gate circuit is connected to the second input end of the second AND gate; the first input end of the second AND gate is connected to the watchdog reset circuit, and the output end of the second AND gate is connected to the CLR end of the dog bite count circuit; The monostable integrated circuit is connected to a first resistor R1 and a capacitor C; the RX-CX terminals of the monostable integrated circuit are respectively connected to the first connection terminal of the capacitor C and one end of the first resistor R1, and the CX terminal and the A_ terminal of the monostable integrated circuit are both connected to the second connection terminal of the capacitor C.

2. According to claim 1, a watchdog biting machine circuit for a multi-machine cold backup system is characterized in that: The CLK end of the dog bite count circuit is connected to the watchdog dog bite signal output end, and is used to record the number of periodic pulses output by the watchdog count circuit, and output a dog bite cut-off instruction after multiple dog bites occur in a single machine.

3. According to the watchdog bite cutter circuit for a multi-machine cold backup system as described in claim 1, it is characterized in that: The other end of the first resistor R1 is connected to the VCC end and the power supply end of the monostable integrated circuit respectively.

4. According to claim 1, a watchdog biting machine circuit for a multi-machine cold backup system is characterized in that: The CLR terminal of the monostable integrated circuit is connected to a second resistor R2.

5. According to claim 1, a watchdog biting machine circuit for a multi-machine cold backup system is characterized in that: The command pulse output circuit adopts a Darlington tube circuit, and the model of the Darlington tube circuit is KG25A.

6. The watchdog biting machine circuit for a multi-machine cold backup system according to claim 1, characterized in that: The QB terminal of the dog bite count circuit is connected to the B terminal of the monostable integrated circuit.

7. The watchdog biting machine circuit for a multi-machine cold backup system according to claim 1, characterized in that: The monostable integrated circuit adopts a monostable trigger of model 54HC123.

8. The watchdog biting machine circuit for a multi-machine cold backup system according to claim 1, characterized in that: The dog bite times counting circuit adopts a 54HC164 chip.

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