JP2002288010A - Monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitoring device capable of accessing a monitored device without affected by the abnormality of a processor. SOLUTION: A full-count signal is outputted from a watchdog circuit 2 when a reset signal outputted from the processor 1 is finished and a counted value reaches a threshold value, and received by a logic circuit 3. The logic circuit 3 outputs a switch control signal to a relay circuit 5 when it receives the full- count signal, and a connecting condition of a switch part 21 is switched to an external connector 6 side when the relay circuit 5 receives the switch control signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device for monitoring the status of a monitored device connected via a cable.

[0002]

2. Description of the Related Art When a monitoring apparatus monitors the status of a monitored apparatus connected via a communication port, a terminal other than the monitoring apparatus, for example, a PC (Personal Computer) or a PDA (Personal Digital Assistant). In the case of updating the program installed in the monitored device by means of ()), the connection between the monitoring device and the monitored device must be temporarily released, and the terminal must be connected to the monitored device. In such a case, the monitoring device must be stopped. However, when a plurality of monitored devices are connected to the monitoring device, the monitoring device cannot be stopped. I couldn't do that. Therefore, a relay circuit is provided inside the monitoring device, and one communication port can be used for different purposes by switching the relay circuit. In addition, RS-2 which is generally used as a communication port
Since 32C does not allow many-to-one connection, the most appropriate method is to physically switch paths using a relay circuit.

[0003]

However, there still remains a problem to be solved in a monitoring device which has a relay circuit as described above and which can use the communication port for different purposes by switching this relay circuit. That is, in the case where the relay circuit is manually switched, when the terminal is connected to the monitored device by the manual switching, there is no response signal to the transmission from the processor of the monitoring device to the monitored device. Therefore, the processor determines that a communication error has occurred, but cannot determine whether the error is due to switching of the relay circuit or an abnormality in the cable or the monitored device. A configuration in which the relay circuit is switched by a processor is also conceivable.In this case, if a failure occurs in the processor, the switching of the relay circuit becomes impossible. Reading cannot be performed. Accordingly, an object of the present invention is to provide a monitoring device that enables switching of a relay circuit by a processor and that can control the relay circuit without being affected by a failure of the processor.

[0004]

According to the present invention, a connector to which a terminal can be connected, a communication port for relaying data output from a processor, and one of the connector and the communication port are provided. And a relay circuit that switches the connection state to a connection state. In the monitoring device that monitors the state of the monitored device via a cable connected to the relay circuit, the monitoring device is reset to an initial value by receiving a reset signal, and is reset from the initial value. A watchdog timer that outputs a full count signal when the count value reaches a threshold,
A processor that outputs a reset signal to the watchdog timer at regular time intervals; and a logic circuit that outputs a switching control signal to the relay circuit when the full count signal is input. . With this configuration, it is possible for the processor to execute the control of the relay circuit, and to prevent the relay circuit from being unable to be switched due to an abnormality in the processor.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a configuration of a monitoring device according to the present invention.
Includes a processor 1, a watchdog circuit 2, a logic circuit 3, a communication port 4, a relay circuit 5, an external connector 6, and a changeover switch 7. Also, in the figure,
One monitored device 12 is connected via a cable 11, and the status of the monitored device 12 is monitored by the monitoring device 10. It should be noted that the monitored device 12 is a disk array device externally connected. The processor 1 controls the entire monitoring device 10, and its operation is determined by a program stored in a nonvolatile memory. The processor 1 has a communication port 4
Also, a request for transmission of monitoring data is issued to the monitored device 12 via. The watchdog circuit 2 is reset by a reset signal from the processor 1 and counts up from 0, and outputs a full count signal to the logic circuit 3 when counting up to a preset value. The logic circuit 3 outputs a switching control signal to the relay circuit 5 when receiving either the relay circuit switching signal from the processor 1 or the full count signal from the watchdog circuit 2.

The communication port 4 relays various commands from the processor 1 to the monitored device 12 and receives data output by the monitored device 12. The relay circuit 5 is a switch for connecting either the processor 1 or the external connector 6 to an external cable. The connection state is controlled based on a switching control signal output from the logic circuit 3. The external connector 6 is a connector for connecting a terminal such as a PC. The changeover switch 7 is for manually switching the relay circuit 5, and is constituted by, for example, a dip switch. Next, the operation of the monitoring device of the present invention having the above configuration will be described. First, when the power switch of the monitoring device 10 is turned on and started, the processor 1 performs an initial setting, and when this is completed, the monitoring operation of the monitored device 12 is started. At this time, the processor 1 also outputs a reset signal to the watchdog circuit 2 every time a predetermined time elapses. When the monitoring device 10 starts the monitoring operation of the monitored device 12, the processor 1 outputs a data transmission request to the monitored device 12 via the communication port 4.

[0007] This data transmission request is taken into the relay circuit 5 via the communication port 4. At this time, the switch state of the relay circuit 5 is set to connect the communication port 4 and the cable 11. The data transmission request is received by the monitored device 12 via the cable 11. When the monitored device 12 receives the data transmission request, the monitored device 12 reads out the data, which is stored in a memory (not shown) and includes the operating state of the fan and the like, and outputs the data to the monitoring device 10. The memory also stores the operation history (communication history and the like) of the monitoring device 10 and is used to analyze the operation state when an abnormality occurs in the monitoring device 10. And the output data is
Received by the monitoring device 10 via the cable 11,
It is stored in an internal memory (not shown) under the control of the processor 1. Such a monitoring device 10 and a monitored device 12
Data transmission to and from is performed at regular intervals,
If any failure occurs in the processor 1, the data transmission request to the monitored device 12 cannot be transmitted, and the output of the reset signal to the watchdog circuit 2 stops. Then, since the count value of the watchdog circuit 2 is not reset, the count value eventually reaches a preset threshold.

When the count value reaches the threshold value, the watchdog circuit 2 outputs a full count signal to the logic circuit 3, and as a result, the logic circuit 3 outputs a switching control signal. When the switching control signal is input to the relay circuit 5, the switching of the path is performed in the relay circuit 5, and the external connector 6 and the monitored device 12 can communicate with each other.
The relay circuit 5 is, for example, as shown in FIG.
It is composed of a switch part 21 and a coil part 22,
When a switching control signal is input from the logic circuit 3, the coil unit 2
2 causes the connection state of the switch unit 21 to move from the communication port 4 side to the external connector 6 side, and the external connector 6 and the cable 11 are connected and the monitored device 1
2 becomes communicable. Thus, processor 1
Because the monitored device 12 also loses input from the monitoring device 10 due to the abnormality of the monitoring device 10, it is recognized that the monitoring device 10 has failed, and the LED (Ligh
t Emitting Diode) is turned on to notify the outside that an abnormality has occurred in the monitoring device 10. The administrator who recognizes that an abnormality has occurred in the monitoring device 10 by turning on the LED, connects a PC or the like to the external connector 6 to analyze the cause of the abnormality that has occurred in the monitoring device 10, and stores it in the memory of the monitored device 12. It is necessary to read the stored operation history,
As described above, since the watchdog circuit 2 outputs the full count signal due to the abnormality occurring in the processor 1 and the relay circuit 5 is automatically switched, the relay circuit 2 is switched due to the abnormality of the processor 1 as before. Since the operation history is not disabled, the operation history can be read.

If no abnormality occurs in the monitoring device 10, the processor 1 switches the relay circuit 5 by switching the changeover switch 7, so that a PC or the like is connected to the external connector 6 to connect the monitored device. 12 can be updated.

[0010]

As described above, in the monitoring device of the present invention, the control of the relay circuit can be executed by the processor, and even if an abnormality occurs in the processor, the relay circuit is automatically connected to the external connector. Since the switching is performed, data transmission / reception with the monitored device can be executed via the external connector.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a monitoring device of the present invention.

FIG. 2 is a diagram showing a configuration of a relay circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Processor 2 ... Watchdog circuit 3 ... Logic circuit 4 ... Communication port 5 ... Relay circuit 6 ... External connector 7 ... Changeover switch 10 ... Monitoring device 11 ... Cable 12 ... Monitored device 21 ... Switch part 22 ... Coil part

Claims (1)

[Claims] 1. A connector to which a terminal can be connected, a communication port for relaying data output from a processor, and a relay circuit for switching one of the connector and the communication port to a connected state. A monitoring device that monitors a state of a monitored device via a connected cable, wherein the watchdog timer is reset to an initial value by receiving a reset signal, and outputs a full count signal when a count value from the initial value reaches a threshold value A processor that outputs a reset signal to the watchdog timer at regular intervals; and a logic circuit that outputs a switching control signal to the relay circuit when the full count signal is input. And monitoring equipment.