JP3570334B2 - System switching device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a system switching device, and in particular, when a failure occurs in a slave bus controller of an active system, switches to a slave bus controller of a standby system by a master bus controller to shut down the system. The present invention relates to a system switching device for preventing the system switching.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a device for relaying an audio signal has two buses, and when one of the bus systems fails, the entire system is switched. In other words, the system is duplicated by the active master bus controller that controls the active slave bus controller and the standby master bus controller that controls the standby slave bus controller, and no data loss occurs when a failure occurs. It has a redundant configuration as shown in FIG. When a failure occurs in the active slave bus controller, the active slave bus controller is switched to the standby slave bus controller.
For example, when the active system and the standby system each have four slave bus controllers (the active system has # 10, # 11, # 12, and # 13, and the standby system has # 20, # 21, # 22, and # 23). When a failure occurs in any one of the slave bus controllers # 10 to # 13 of the working system, instead of switching only one of the failed systems to the standby system, the occurrence of the failure indicates that the working system has failed. Of the slave bus controllers # 10 to # 13 are replaced with all of the slave bus controllers # 20 to # 23 of the standby system.
[0003]
[Problems to be solved by the invention]
However, according to the conventional system switching device, when a failure occurs in the active slave bus controller and the system is switched to the standby system, if one of the standby system slave bus controllers fails, the standby system Of the master bus controller notifies the active system of the occurrence of the fault. For this reason, switching to the standby system is not performed, and a state in which a slave error signal is output in both the active system and the standby system occurs, and both the active system and the standby system may go down. Such a situation becomes a problem in a highly public system.
[0004]
An object of the present invention is to provide a system switching device capable of preventing both the active system and the standby system from being shut down when a failure occurs in the standby system when the active system is switched to the standby system. To provide.
[0005]
[Means for Solving the Problems]
According to the present invention, in order to achieve the above object, an active master bus controller and a standby master bus controller are connected to each other, and each of the master bus controllers includes a plurality of slave bus controllers. When a failure occurs in a slave bus controller, the system switching device for switching from the active system master bus controller to the standby system slave bus controller by the active system and standby system master bus controllers includes the standby system slave bus controller. When switching to the standby system, when a failure has occurred in the standby system slave bus controller, control means is provided for inhibiting switching to the standby system and continuing the operation of the active system slave bus controller. System switching equipment .
[0006]
According to this configuration, when a failure occurs in the active slave bus controller and also in the standby slave bus controller, the control unit switches the system from the active system to the standby system. And the operation is maintained as it is. This can prevent both the active system and the standby system from going down.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a system switching device according to the present invention.
The system switching device includes a master bus controller 100 as an active system, a master bus controller 200 as a standby system, slave bus controllers 130, 140, 150, and 160 whose operation states are monitored by the master bus controller 100, and a master bus controller 200. The slave bus controllers 230, 240, 250, and 260 whose operation states are monitored by the controller are configured. The master bus controller 100 and the master bus controller 200 are mutually connected.
[0008]
The master bus controller 100 includes a slave bus controller status monitoring unit 110 and a master bus controller status monitoring control unit 120. The slave bus controller status monitoring unit 110 receives a slave fault signal 112 from the slave bus controllers 130 to 160. Similarly, the slave bus controller includes a slave bus controller status monitoring unit 210 and a master bus controller status monitoring control unit 220. The slave bus controller status monitoring unit 210 receives a slave fault signal 212 output from the slave bus controllers 230 to 260. Is entered.
The slave bus controller status monitoring unit 110 turns on the active slave status signal 111 transmitted to the slave bus controller status monitoring unit 210, and further turns on the slave error signal 101 transmitted to the master bus controller status monitoring and control unit 120. I do. In response to this, the master bus controller status monitoring control unit 120 turns on the system switching signal 121. The system switching signal 121 is received by the master bus controller status monitoring control unit 220, and the master bus controller 100 executes switching to the standby system.
[0009]
FIG. 2 shows the processing timing of the system switching device of FIG.
With reference to FIG. 2, the operation of the system switching device having the configuration of FIG. 1 will be described below.
Under normal conditions, the slave fault signals 112 from the slave bus controllers 130 to 160 are OFF. When a failure occurs in any of the slave bus controllers 130 to 160 (S11), the slave failure signal 112 of the failed slave bus controller is turned on (S12). At this time, if the standby slave status signal 211 output from the slave bus controller status monitoring unit 210 is OFF, the slave bus controller status monitoring unit 110 of the master bus controller 100 turns ON the slave error signal 101 (S13). When the master bus controller status monitoring control unit 120 receives this, the system switching signal 121 is generated (S14), whereby switching from the active system to the standby system is performed (S17).
[0010]
However, when a failure occurs in any one of the slave bus controllers 230 to 260 of the master bus controller 200 (S15) and the slave failure signal 212 of the slave bus controller is turned on, the master of the master bus controller 200 becomes The bus controller status monitor 210 turns on the standby slave status signal 211 to be sent to the slave bus controller status monitor 110 (S16). Thereby, the slave bus controller status monitoring unit 110 determines the status of the standby system, and forcibly turns off the slave error signal 101 (S18). When the slave error signal 101 is turned off, switching from the active system to the standby system is not performed (S19), and the operation by the active system slave bus controller is continued (S20). At this time, the operation of the system of the slave bus controller in which the failure of the active system has occurred is stopped, but the system of the normally operating slave bus controller of the active system can be continuously used. Therefore, even if a partial down occurs, a situation in which the entire system goes down is avoided.
[0011]
FIG. 3 shows an application example of the system switching device of the present invention.
Here, an audio signal relay device is taken as an application object. The system switching device 300 according to the present invention is incorporated in the bus system of the relay device. The relay device 500 is provided between the upper device 400 and a lower device (not shown), and has a three-shelf configuration including an upper shelf 510, a # 0 shelf 520, and a # 1 shelf 530. The upper device 400 is, for example, an exchange (base station) in a network or a circuit system, and the lower device is a portable terminal or the like. The upper shelf 510 includes a line interface 511, the # 0 shelf 520 includes line relay circuits 521 to 523, and the # 1 shelf 530 includes line relay circuits 531 to 533. For example, each channel of a communication line is connected to these line relay circuits. The system switching device 300 is shared by the upper shelf 510, the # 0 shelf 520, and the # 1 shelf 530, but operates in either the active system (master bus controller 100) or the standby system (master bus controller 200). Yes, the other is waiting.
[0012]
A signal from the host device 400 is transmitted to the master bus controller 100 and 200 by the line interface 511. Since the master and slave bus systems have a redundant configuration, they have a circuit for switching from the active system to the standby system. The master bus controller 100 is connected to the slave bus controllers 130 and 140 of the # 0 shelf 520, and the master bus controller 200 is connected to the slave bus controllers 230 and 240 of the # 1 shelf 530. Signals from the master bus controllers 100 and 200 are sent from the slave bus controllers 130, 140, 230 and 240 to the line relay circuits 521 to 523 and 531 to 533 and relayed to lower-level devices.
[0013]
Next, the operation of the system of FIG. 3 will be described with reference to FIG.
The master bus controller 100 constantly monitors the status of the slave bus controllers 130 and 14. When a failure occurs in one of the slave bus controllers 130 and 140 due to an external factor, the slave bus controller turns on the slave failure signal 112 and notifies the master bus controller 100 of a state change. The slave fault signal 112 is received by the slave bus controller status monitoring unit 110, and the slave bus controller status monitoring unit 110 turns on the active slave status signal 111 and turns on the slave error signal 101. In response to the slave error signal 101 being turned on, the master bus controller state monitoring controller 120 turns on the switching signal 121. As a result, the master bus controller is switched from the active system to the standby system.
[0014]
At the time of switching to the standby system, if a failure occurs in any of the standby slave bus controllers 230 and 240, the master bus controller 200 turns on the standby slave status signal 211 by the master bus controller status monitoring unit 210. Then, the switching prohibition is notified to the slave bus controller status monitoring unit 110 of the master bus controller 100. In response to this notification, the slave bus controller state monitoring unit 110 forcibly turns off the slave error signal 101 so as not to switch to the standby system so that the slave error signal 101 does not turn on. In addition, as a post-process, the administrator performs recovery work (inspection, repair, replacement, etc.) of the slave bus controller in which the failure of the active system and the standby system has occurred.
[0015]
In the configuration shown in FIG. 3, it is unlikely that two slave bus controllers of the active system and the standby system will fail at the same time. However, if the power of the shelf is turned off, two slave bus controllers will fail simultaneously. In such a case, the provision of the switching prohibition device 300 according to the present invention allows another shelf to be in an operation state. For example, when a failure occurs in the slave bus controller 130 and the master bus controllers 100 and 200 attempt to switch from the active slave bus controllers 130 and 140 to the standby slave bus controllers 230 and 240, the slave bus controller 230 fails. Does not switch to the standby slave bus controllers 230 and 240, the subsequent operation is performed only by the normal working normal slave bus controller 140. Therefore, the # 0 shelf 520 goes down, but the # 1 shelf 530 stays down.
[0016]
FIG. 4 shows details of the configuration of the slave bus controller status monitoring unit 110 of FIG. Here, only the active system side is shown, but the configuration of the standby system slave bus controller status monitoring unit 210 is the same.
One of the open collectors (Open Collector, hereinafter referred to as O / C) of the NAND gates 301, 302, 303, 304 to which the output terminals are commonly connected has slave fault signals # 0, # 1, # as the slave fault signal 112. 2, # 3 are input, and resistors 305, 306, 307, 308 are connected between each of these input lines and the ground. Each of the other O / Cs of the NAND gates 301 to 304 is pulled up to the power supply Vcc. A resistor 313 is connected between the output terminals of the NAND gates 301 to 304 and the ground. Further, an inverter 314 and a buffer 315 are connected to output terminals of the NAND gates 301 to 304. The output terminal of the inverter 314 is connected to one input terminal of the NAND gate 316, and the other input terminal of the NAND gate 316 is connected to the output terminal of the buffer 317. As an output signal of the NAND gate 316, the slave error signal 101 is output . Slave state signal 211 of the standby system is input to the bus Ffa 317, its output signal becomes a slave state signal 111 of the active system. The reason why the pull-down processing is performed in the NAND gates 301 to 304 is to make it possible to regard a failure even at the time of reset and at the time of non-mounting.
[0017]
Next, the operation of the system switching device of the present invention will be described with reference to FIGS.
The slave bus controllers 130 to 160 are normally at the “L” level, and when in the failure state, are at the “H” level (high impedance state). For example, when the slave bus controller 140 enters a failure state due to an external factor, the slave failure signal # 1 goes to “H” level. Therefore, one input terminal of the NAND gate 302 is set to the “H” level, and the other input terminal is also pulled up to the “H” level by the resistor 309, so that the output terminal of the NAND gate 302 is set to the “L” level. Become. This signal becomes the “L” level slave signal 111 through the buffer 315, and becomes the active slave state signal 111 for transmitting the failure of the active system to the standby system. Further, the output signal of NAND gate 302 is inverted by inverter 314 to attain an "H" level.
[0018]
At this time, the slave status signal 211 of the standby system is input to the buffer 317 from the slave bus controller status monitoring unit 210. If all of the standby slave bus controllers 230 to 260 are in a normal state, the standby slave state signal 211 is at "H" level, indicating "standby normal". Therefore, both inputs of the NAND gate 316 become "H" level, and the slave error signal 101 as an output signal thereof becomes "L" level. Upon receiving this signal from the slave bus controller status monitoring unit 110, the master bus controller status monitoring control unit 120 determines that the active slave has a fault, turns on the system switching signal 121, and switches to the standby system.
[0019]
On the other hand, if any of the slave bus controllers 230 to 260 in the standby system enters the fault state, the slave status signal 211 in the standby system becomes “L” level, indicating that the fault has occurred in the standby system. If the standby slave state signal 211 is at "L" level, the output of the NAND gate 316, that is, the slave error signal 101 becomes "H" level regardless of the level state of the output signal of the inverter 314, and the active slave Bus controller faults are masked. As described above, even when a failure occurs in the active slave bus controller, if any of the standby slave bus controllers has a failure, switching to the standby system is not performed.
[0020]
【The invention's effect】
As described above, according to the system switching device of the present invention, when a failure occurs in the standby slave bus controller while a failure occurs in the active slave bus controller, the control unit switches from the active system to the standby system. Since the switching to the standby system is not performed, the system can be prevented from going down even when a failure occurs in both the active system and the standby system. In addition, since the control can be performed only by the master bus controller without taking care of the host device, the system is not enlarged.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a system switching device according to the present invention.
FIG. 2 is an explanatory diagram showing processing timing of the system switching device of FIG. 1;
FIG. 3 is a block diagram showing an application example of the system switching device of the present invention.
FIG. 4 is a circuit diagram showing details of a configuration of a slave bus controller status monitoring unit of FIG. 1;
[Explanation of symbols]
100, 200 Master bus controller 101, 201 Slave error signal 110, 210 Slave bus controller status monitor 112, 212 Slave fault signal 120, 220 Master bus controller status monitor controller 121, 221 System switching signal 130, 140, 150, 160 Slave bus controllers 230, 240, 250, 260 Slave bus controller 300 System switching devices 301-304, 316 NAND gate 314 Inverter 315, 317 Buffer

Claims (2)

An active master bus controller and a standby master bus controller are connected to each other, each of the master bus controllers includes a plurality of slave bus controllers, and when the active slave bus controller fails, the active master bus controller In a system switching device for switching from the active master bus controller to the standby slave bus controller by an active and standby master bus controller,
When switching to the standby system slave bus controller, when a failure occurs in the standby system slave bus controller, control for inhibiting switching to the standby system and continuing the operation of the active system slave bus controller With means,
A slave bus controller status monitor that generates a slave status signal when a slave fault signal indicating that a fault has occurred is input from the slave bus controller; and the slave bus controller status monitor. A master bus controller status monitoring control unit that transmits a system switching signal to the partner system based on a slave error signal from
The active and standby slave bus controller status monitoring units are mutually connected to each other's slave bus controller status monitoring units, and generate the own system slave status signal using the own system slave fault signal as an input condition. And a circuit for generating a slave error signal by taking a logic of the slave status signal of the other system and the slave status signal of the own system output from the NAND gate of the other system. Switching device. 2. The system switching device according to claim 1, wherein said NAND gate is of an open collector type.

Images