JPH0650502B2 - Automatic operation switching control system for multiplexer system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an automatic operation switching control system for a multiplexer system, that is, in order to improve the reliability of operation, a plurality of devices, particularly computers, are provided for multiplexing. The present invention relates to a system for automatically selecting a plurality of devices in a system and switching the operation of the system to the selected device.

[Conventional technology]

The above-mentioned equipment multiplexing, usually duplication, is often performed when high operational reliability is required for the equipment, but it is meaningless to simply provide a plurality of equipment, and operation or management as a multiple equipment system. If it is not done, the effect of improving operational reliability cannot be obtained. There are two main functions required for operation as this system: monitoring of operating conditions and switching or selection of operating devices based on the results. FIG. 3 shows the structure of a general conventional example of a duplexer system having these two functions.

In the figure, the two devices are designated by the reference numerals 1 and 2, and monitoring circuits 1a and 2a are attached to them respectively. Each of the monitoring circuits 1a and 2a monitors a plurality of pieces of monitoring information I from the devices 1 and 2 to which the monitoring circuit 1a and 2a belong, and whether or not the operating state of the device is normal, and also monitors the monitoring status of the other monitoring circuit. Or watch the results. In other words, each monitoring circuit, for example 1a, monitors not only the device I to which it belongs but also the operating state of the device 2 of the other party, and if there is an operational abnormality in the other device 2, the monitoring circuit 2a attached thereto will be used. Knowing this, it notifies the device I to which it belongs of that notification N.

The above is the monitoring function. As a result, the device, for example, 1, which has received the notification from the attached monitoring circuit that the partner device has an abnormality, issues a switching command CS to the switching control circuit 4 of the switching circuit 3. This switching command CS is lost as long as the other device is operating normally, but is a so-called request command for the driving right issued when it is not so, and is usually shown between each device and the switching control circuit 4. Two lines have been drawn and can be placed on any of these lines. This switching command CS
There are two lines for the purpose of preventing the switching commands from both devices 1 and 2 from being simultaneously issued to the switching control circuit 4 and making it impossible to determine which device is given the operating right. Change command that can be put on these two lines like CS1,
If it is CS2, for example, it is pre-arranged that the switching command CS2 has a higher priority than the switching command CS1, and one of the two devices 1 and 2 is given a low priority switching command CS1 and the other is given a high priority. It is specified or assigned in advance that the switching command CS2 should be issued. Therefore, the device 1
Will issue a switching command of the priority assigned to it, and it is assumed that this is the switching command CS1. On the other hand, since the device 2 is in a state in which the request for the driving right is satisfied as long as it is in operation, the switching command as the request command is not issued. Therefore, in the present case, the switching command is issued only from the device 1, and the switching control circuit 4 receiving this command gives the driving right to the device 1 without hesitation even if it is the switching command CS1 having a low priority. A selection command SS indicating that it is given is sent to the changeover switch 5. The changeover switch 5 connects the driving line or the bus L to either the driving line L1 on the device 1 side or the driving line L2 on the device 2 side, and the switching position thereof is not shown in response to the above selection command SS. The operation of the system is switched to the device 1 side by reversing. When both devices 1 and 2 are not in an operating state such as when the system is started, and a switching command is issued from both devices to the switching control circuit 4 at the same time, the switching control circuit 4 outputs the switching command with high priority. The device that issued CS2, for example device 2
Select. Of course, the setting of which of the two devices is given a higher priority can be changed at any time.

[Problems to be Solved by the Invention]

In the above-mentioned conventional example, the operational monitoring function of the multiplex device system is fulfilled by the supervisory circuit attached to each device, but each supervisory circuit is of course not limited to the operating state of the device to which it is attached. Since the operating state of the device must also be monitored via the monitoring circuit attached to the device, the structure of the monitoring circuit is not simple, and the number of devices in the multiplexing device system increases and the problem tends to be complicated. In addition, the success or failure of the operation management of the multiplexer system depends on the function of this monitoring circuit, so the monitoring circuit is required to have high operation reliability. Normally, the monitoring circuit is also multiplexed to guarantee its operation reliability. Must. On the other hand, the selection of operating devices or the priority management function in the operation of the multiplexing device system is mainly shared by each device constituting the system, and the switching control circuit in the switching circuit receives a switching command from each device. Since only the changeover switch is changed in response to the fidelity, if there is a contradiction between the devices in the priority management or if this management malfunction occurs in a certain device, the operation of the system will be confused. Therefore, there is a problem that the priority management in each device is not so easy, and this priority management must be incorporated in all the devices in the system. In addition, as a system operation, a plurality of devices may be operated at the same time, and in this case, priority management within each device becomes more complicated. Of course, there are various methods for operation management of the multiplexer system other than the example shown in FIG. 3, but almost all of them have the above-mentioned problems more or less.

An object of the present invention is to solve the above problems and obtain an automatic operation switching control system of a multiplexer system having a simple structure and high operational reliability.

[Means for Solving the Problems]

According to the present invention, the above-mentioned problem is to provide a setting means capable of setting a plurality of operating priority levels common to all the devices in the multiplexing device system and setting the priority levels in each device, A selection device is provided commonly to all devices in the system, and each device and this selection device are connected by a control line, and the setting means sets a level selected from a plurality of priority levels to each device. Then, as long as it can be operated normally from each device, a level signal indicating the priority level set in the setting means is continuously sent to the selection device through the control line, and a plurality of devices are provided on the selection device side. The system is selected based on the priority level indicated by the level signal received from the device and the first-come-first-served basis of the level signal, and the operation of the device is switched by putting the selected device into operation.

In implementing the method of the present invention, frequencies different from each other are assigned to each priority level, and a level signal of a frequency corresponding to the priority level set by each device is placed on the control line to select the device. It is particularly advantageous to send it to. In addition, as an advantageous mode for selecting a device by the selection device, it is desirable that the device which has the highest priority level among the level signals received by the selection device and has issued the earliest arrival level signal is selected.

[Action]

As described above, according to the present invention, setting means is provided in each device, and each device simply outputs a level signal indicating the priority level set by the setting means. Eliminating the need for each device to share a rather trivial priority management function, each device is allowed to keep this level signal on the control line as long as it can operate normally, and when it disappears It makes it easy to detect abnormalities in equipment, eliminates the need to monitor the operating status of other equipment by providing a monitoring circuit attached to each equipment as in the past, and selects operating equipment including priority management. Or, the switching function is centrally handled by the selection device provided in common to all the devices in the system, so that inconsistency in management and various troubles may occur while centralizing and simplifying priority management. By substantially eradicate room, but successful in solving the aforementioned problems.

〔Example〕

The embodiments of the present invention are described above with reference to the drawings. FIG. 1 is a block circuit diagram of a configuration example of a multiplexing device system which implements the method of the present invention, and FIG. 2 is a circuit diagram showing a specific example of a selection device.

In FIG. 1, three devices 10, 20, 30 are shown in this example as devices constituting a multiplexing device system, and these devices are, for example, computer systems, and each device 10, 20 Setting means 11, 21 and 31 for setting the priority levels in operation according to the present invention are respectively provided in the terminals 30 and 30. From these devices 10, 20, 30
L1, L2, L3 are derived, and in this example, a changeover switch 60 connects any one of them to the operation line L. These operating lines are all bidirectional buses or signal lines when the device is a computer. Normally, the device is operated alternatively as in this example, but in some cases, a plurality of devices may be operated in parallel at the same time. In this case, the function of the changeover switch is separated for each device and the operation line is separated. A switch for connection with L is provided for each device so that connection and disconnection can be performed independently of each other.

A selection device 40 is provided commonly to all the devices in the system, and each device 10, 20, 30 is connected to the selection device 40 by one control line 51, 52, 53 in this embodiment. These control lines 51, 52, 53 are for transmitting the level signals CS1, LS2, LS3 indicating the level of the priority assigned to each device 10, 20, 30 to the selection device 40, respectively. Further, in this embodiment, these level signals LS1, LS2, LS3 are transmitted in the form of signals having mutually different frequencies f1, f2, etc. indicating the priority levels, respectively. Is simply shown.

The frequency divider or counter 12 shown in the frame of the device 1 receives the basic clock pulse CP in the device and generates a pulse train having three frequencies f1, f2, f3 from its final stage. Therefore, the setting means 11 is a changeover switch in this example, and one of these frequencies is taken out as the level signal LS1 so that the priority level of the device 1 can be set. The switch 14 is, for example, a normally open switch, and is closed by the monitoring circuit 13 shown above as long as the device can be normally operated or is operating.
The pulse train of the frequency set by the setting means 11 serves to continuously put on the control line 51 as a level signal LS1 indicating the priority level of the device 1. Obviously, the monitoring circuit 13 receives a plurality of pieces of monitoring information I inside the device 1 and monitors from them whether the operating state of the device is normal, or whether it can be operated normally. In the invention, it is not necessary to give it the role of monitoring the operating states of other devices as in the prior art. It should be noted that the function of the changeover switch as the counter 12 and the setting means 11 can be incorporated as software so that the device 1 can be easily understood when it is a computer, and the priority level assigned to the device need not always be one. Alternatively, it is possible to set a plurality of them as needed. The setting of the plurality of priority levels is convenient when the apparatuses are operated in parallel, and the priority level is set for each job performed by the apparatus 1, for example. However, in this case, it is necessary to provide a plurality of control lines correspondingly.

The selection device 40 that receives the level signals LS1 to LS3 generated as described above via the control lines 51 to 53, respectively, selects the device based on the priority level indicated by these level signals and the first-come-first-served basis of the level signals. Then, in this example, the selection command SS indicating the selection result is sent to the changeover switch L to put the selected device into operation, and generally, it may be configured by using a microcomputer. Second
The figure shows an example in which this is configured using logic gates. For simplification, the number of devices included in the system is 2 and the number of priority levels is 2.
The figure shows the case where there is one control line for each device. Hereinafter, when the selection command SS is “H”, the changeover switch 60 connects the operation line L to the operation line L1 for the device 10,
The operation of the selecting device 40 shown in the figure will be described assuming that the driving line L2 for the device 20 is connected when "L". Two frequencies f1 and f2 are used as the frequencies indicating the priority level, and the latter has a higher priority.

The selecting device 40 shown in the figure receives level signals LS1 and LS2 from the left side thereof via control lines 51 and 52 to their frequency detecting circuits 41 and 42, respectively, and both frequency detecting circuits 41 and 42 receive the level signal L.
Depending on whether the priority level by S1, LS2 is indicated by frequency f1 or f2, its detection signal
Set FS1 or FS2 to "H". Level signal LS1 or LS2
When is eliminated, both the detection signals FS1 and FS2 from the frequency detection circuit 41 or 42 are "L". As can be easily understood, such a frequency detection circuit can be easily achieved by, for example, a counter that counts the number of pulses in a level signal that is a pulse train within a fixed time and a comparison circuit that compares the count result with a predetermined number.

On the right side of the frequency detection circuit are flip-flops 4 each composed of two NAND gates and one inverter.
2,43 and one NOR gate 44 are shown. The flip-flop 42 is set and reset by the two detection signals FS1 from the both frequency detection circuits 41 and 42 corresponding to the frequency f1 showing low priority, and both level signals LS1 and LS2 have low priority. When it is at level f1, it plays a role of deciding the first-come-first-served basis. For example, when the device 1 issues the level signal LS1 of the lower priority level f1, the output becomes “H”, and in the opposite case. It becomes "L". The flip-flop 43 is for determining the first-come-first-served order when both the level signals LS1 and LS2 simultaneously show the high priority level f2, and is set by the two detection signals FS2 from the frequency detection circuits 41 and 42.
When the level signal LS1 is reset and the level signal LS1 is the first-arrival, its output becomes "H". NOR gate 44 detects signal FS2
Is to be prioritized over the detection signal FS1, and two detection signals FS2 from both frequency detection circuits 41 and 42 are input, and both are “L”, that is, one of the level signals LS1 and LS2. Also causes its output to go "H" and enable the AND gate 45 shown to its right only if no higher priority level f2 is specified. Conversely, the level signal
When either LS1 or LS2 indicates a high priority level f2,
The AND gate 45 is closed and the output from the flip-flop 42 is ignored. The OR gate 46 which outputs the selection command SS receives the output of the AND gate 45 and the output of the flip-flop 43 for high priority level.

As can be seen from the above, the selection device 40 shown
When the higher priority level f2 is designated by at least one of LS1 and LS2, the output of the flip-flop 43 is issued as it is as the selection command SS. AND gate 45 when high priority level f2 is not specified for both level signals.
Is enabled and the output of the flip-flop 43 becomes "L", so that the flip-flop 42 for low priority level is directly output as the selection command SS. Further, when both the low priority level f1 and the high priority level f2 are designated by both of the level signals LS1 and LS2, the first-arrival level signal is always selected, and the first-level signal LS1 is selected. In this case, the selection command SS becomes "H" and the device 1 is selected. In the opposite case, the selection command SS becomes "L" and the device 2 is selected. That is, in this example, the selection device 40 selects the device which has the highest priority level in the level signals and has issued the first-arriving level signal.

Of course, the selection function provided to the selection device 40 is not limited to the above-described aspect, and various selection functions may be provided depending on the number of devices that configure the system, the number of priority levels that can be set, and whether or not the devices are operated in parallel. This selection device can be provided. If this is to have a complicated selection function, it is advantageous to use the microcomputer as described above in the portion excluding the frequency detection circuit of the selection device and incorporate the necessary functions into it as software. In any case, in the system of the present invention, the selection of the operating device is centrally managed by this selecting device which is provided commonly to the devices in the system.

Returning to FIG. 1, the multiplexer system using the selection configured as described above is configured such that one of priority levels f1 to f3 is set by the setting means 11 in each of the devices 10, 20, 30 in this example. It is operated in the set condition. This setting may, of course, be used for multiple devices with the same priority level, and if necessary, it is permissible to change this setting while the system is operating unless it causes the system to stop operating. . If an abnormality occurs during operation of a device, the monitoring circuit in that device
Since 13 detects this and eliminates the level signal from that device, the selection device 40 is based on this that the device with the same priority level as the operating device is selected, which is lower if it is not. A device for which the priority level is set is selected, and the changeover switch 60 is operated by the selection command SS to automatically switch the operation of the system to this newly selected device. Also, if necessary, by changing the setting of the priority level of the desired device during operation of the system so as to be higher than the priority level of the device currently in operation, as described above,
The operation of the system can be switched to the desired device.

As can be understood from the above description, the method of the present invention is not limited to the embodiment and can be implemented in various modes. For example,
In the embodiment, different frequencies are assigned to the respective priority levels, but as in the conventional case, a plurality of control lines are provided for each device, and a level signal is sent to the selection device via a separate control line for each priority level. It is also possible to send it.

〔The invention's effect〕

As described above, according to the present invention, in the automatic operation switching control system of the multiplex device system which automatically selects a plurality of devices and switches the operation of the system to the selected device, it is common to all the devices in the system. A plurality of operating priority levels are arranged and each device is provided with setting means capable of setting this priority level, and a selecting device is provided in common in all the devices in the system so that each device and this selecting device are connected to each other. Each of them is connected with a control line, and a level selected from a plurality of priority levels is set for each device by the setting means, and then each device is set to the setting means as long as it can be operated normally. Based on the priority level indicated by the level signals received from the plurality of devices and the first-come-first-served basis of the level signals, the level signal indicating the selected priority level is continuously transmitted to the selection device through the control line. Select the device, Since the operation of the device is switched by putting the selected device into operation, the device is ready to output a simple level signal indicating the priority level selected by the setting means. As long as it is issued, each device has a monitoring circuit attached to each device that has a function of monitoring the operating status of other devices, or each device has its own priority management function. This eliminates the need for the system and greatly simplifies the entire system configuration. Since the priority management and operating device selection functions in the system are performed centrally by the selection device that is provided in common to all devices in the system, there are inconsistencies in priority management and various unexpected troubles as in the past. There is virtually no room for the occurrence of the above-mentioned problems by the practice of the present invention. Further, as can be seen from the embodiment, the selection device may have a simple structure,
This can have high operational reliability.

Further, according to an advantageous aspect of the present invention in which the priority levels are represented by frequencies different from each other, even if the number of priority levels is increased to increase the operational flexibility of the system, the priority level between each device and the selection device is increased. The control line can be a single line, which is convenient because the amount of wiring between devices can be small, especially when the distance between devices is large.

As described above, by adopting the method of the present invention, it is possible to obtain a remarkable effect that the structure of the multiplexer system can be simplified and its operation reliability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 relate to the present invention, and FIG. 1 is a block circuit showing a configuration example of a multiplexer system implementing an automatic operation switching control system of a multiplexer system according to the present invention. FIG. 2 is a circuit diagram of an embodiment in which the selection device constituting the method of the present invention is composed of an electronic circuit. FIG. 3 is a schematic configuration diagram of an example of an automatic operation switching control system for a multiplexer system according to the prior art. In the figure, 1,2: device, 1a, 2a: monitoring circuit, 3: switching circuit, 4:
Changeover control circuit, 5: Changeover switch, 10, 20, 30: Device, 1
1,21,31: Setting means, 12: Counter, 13: Monitoring circuit, 1
4: Level signal switch, 40: Selection device, 41, 42: Frequency detection circuit, 42, 43: Flip-flop, 44: NOR gate, 45: AND gate, 46: OR gate, 50, 51-53:
Control line, 60: Changeover switch, CP: Clock pulse, CS, C
S1, CS2: Switching command, I: Monitoring information, FS1, FS2: Frequency detection signal, f1 to f3: Frequency indicating priority level, L, L1 to
L3: driving line, LS1 to LS3: level signal, N: notification, SS: selection command.

Claims (1)

[Claims] 1. A method for automatically selecting a plurality of devices in a multiplex device system and switching the operation of the system to this selected device, wherein the operation priority level is common to all the devices in the system. A plurality of arrangements are arranged and each device is provided with a setting means capable of setting this priority level, and a selection device is provided in common in all the devices in the system, and a control line is provided between each device and this selection device. In conclusion, after setting the level selected from a plurality of priority levels for each device by the setting means, as long as it can be operated normally from each device, the priority level set in the setting means is set. The level signal shown is continuously sent to the selection device via the control line, and the selection device selects the device based on the priority level indicated by the level signals received from the plurality of devices and the first-come-first-served basis of the level signals. Put the selected device into operation. Multiplexer system automatic operation switching control method being characterized in that so as to switch the operation of the apparatus by.