JPH1063387A - SCSI bus terminator connection control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To automatically change the position of a terminator when the power of a device is turned off to eliminate signal disturbance of a SCSI bus,
The purpose is to ensure the reliability of the system. SOLUTION: A plurality of information processing devices 1 and ₂ are connected by SCSI buses 3 ₁ and 3 ₂ , and first terminators 5 ₁ and 2 built in each information processing device are provided at both ends of the SCSI bus.
In SCSI bus terminator connection control unit for connecting 5 _2, the information processing apparatus corresponding to electrically connect the SCSI bus to each other switch means 12a is always derived from the information processing apparatuses, 12b and the second terminator 5 _The peripheral device ₄ having the built-in ₃ and 54 and the power supply state of each information processing device are monitored, and when the power supply of any one of the information processing devices is off, the switch means corresponding to the information processing device on the power-off side. And a terminator position changing means 6 for changing the connection of the end of the SCSI bus derived from the information processing device on the power supply side to the second terminator instead of the first terminator. This is a SCSI bus terminator connection control device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a SCSI (Small)
The present invention relates to a SCSI bus terminator connection control device for connecting a plurality of information processing devices using a bus.

[0002]

2. Description of the Related Art A SCSI bus has a relatively short length, and about 10 information processing devices can be connected by arbitrarily combining an input / output channel (host adapter) and an input / output device adapter. It is a bus.

FIG. 7 is a block diagram of a conventional SCSI bus terminator connection control device using such a SCSI bus. In this control device, a first information processing device 51 and a second information processing device 52 are connected to a peripheral device 54 via a SCSI bus 53, and one of the information processing devices 51 and 52 is Is used as a master, and the other information processing device is operated as a slave, and executes predetermined processing while sharing, for example, a hard disk and other peripheral devices 54 having uses and functions.

When the above SCSI bus is used, it is necessary to terminate both ends of the bus with a terminator 55 having a predetermined impedance. For example, in a system as shown in FIG.
And the second information processing device 52 sandwich the peripheral device 54 with S
Although connected by the CSI bus 53, in such a case, both ends of the SCSI bus 53 are connected to the information processing devices 51 and 5, respectively.
2, both ends of the SCSI bus 53 are terminated by terminators 55 built in the information processing devices 51 and 52.

However, when any one of the two information processing devices 51 and 52 becomes abnormal,
When the power of the information processing device that becomes abnormal is turned off, the SC
Since the end of the SI bus 53 is open, the peripheral device 5
4. It is necessary to terminate the end of the SCSI bus 53 using the built-in terminator 55.

Therefore, conventionally, a switching operation output device 56 is provided, for example, when the first information processing device 51 is abnormal,
The information processing device 52 detects an abnormal state of the first information processing device 51 and generates an alarm. Here, the operator
It is determined from the alarm state of the second information processing device 52 that the first information processing device 51 is abnormal, and the power on / off control switch 5
7, the power of the first information processing device 51 is turned off from the switching operation output device 56 through the control signal line 59, while the connection control switch 58 is operated to send an operation signal to the peripheral device 54, A terminator 55 built in a peripheral device is connected to the end of a SCSI bus 53 connected to the information processing device 52 side.

[0007]

Accordingly, the above-described SCSI bus terminator connection control device has a power ON / OFF control switch 57 and a connection control switch 58 depending on the human system.
Is operated, the switch to be operated is mistaken, for example, not the second information processing device 52 but the first information processing device 51.
When the terminator 55 is connected to the end of the SCSI bus 53 connected to the other side, or the SCSI bus 53 is removed by replacing the board due to an abnormality in the first information processing apparatus 51 without performing a switch operation. In addition, there is a problem that the end of the SCSI bus 53 is opened, the signal on the bus fluctuates, and a bus error occurs.

Further, when the first information processing device 51 becomes abnormal during normal operation, for example, the first information processing device 51 has already accessed the SCSI bus 53, There is a problem that an abnormal drive signal is superimposed and data transmission by the second information processing device 52 cannot be performed normally.

The invention described in claim 1 has been made in view of the above circumstances, and automatically changes the position of the terminator when the power of the apparatus is turned off to secure an optimal bus state.
An object of the present invention is to provide a SCSI bus terminator connection control device which eliminates the influence of noise and cable attachment / detachment and improves reliability.

According to a second aspect of the present invention, when an information processing device is abnormal, the device on the abnormal side is disconnected,
S in which the information processing device on the normal side can properly transmit data
An object of the present invention is to provide a CSI bus terminator connection control device.

According to a third aspect of the present invention, an SCS that automatically secures an appropriate bus state when the power of the information processing apparatus is turned off or when an abnormality occurs, thereby ensuring system operability and reliability.
An object of the present invention is to provide an I bus terminator connection control device. A fourth object of the present invention is to provide a SCSI bus terminator connection control device which constantly monitors the state of the bus and can grasp the operation state of each device.

[0012]

According to a first aspect of the present invention, a plurality of information processing devices are connected by a SCSI bus, and both ends of the SCSI bus are terminated by a first terminator built in each information processing device. A SCSI bus terminator connection control device that includes a switch device and a second terminator corresponding to an information processing device for electrically connecting the SCSI buses that are normally derived from the information processing devices, and The power supply state of each information processing device is monitored, and when the power of any one of the information processing devices is off, a switching control signal is sent to the switch unit corresponding to the information processing device on the power off side, and the power supply on the power on side is turned off. A terminator for terminating the second terminator in place of the first terminator at the end of a SCSI bus derived from an information processing device SCS provided a chromatography data position changing means
It is an I bus terminator connection control device.

In the invention corresponding to claim 1, the terminator position changing means receives a power on / off signal from each information processing device by taking the above means. When the power of one information processing device is off, a switching control signal is sent to the switch means corresponding to the information processing device on the power off side, and the switching control signal is sent from the SCSI bus side derived from the information processing device on the power off side. By switching to the 2 terminator, the distance of the SCSI bus is set to the shortest state, so that it is less susceptible to noise, and the disturbance of the SCSI bus due to the attachment / detachment of the cable can be prevented, and the reliability is improved. be able to.

According to a second aspect of the present invention, there is provided an apparatus which includes a switch means and a second terminator corresponding to an information processing apparatus for electrically connecting the SCSI buses which are normally derived from each information processing apparatus. Monitoring the operation state of each of the information processing devices, and when any one of the information processing devices becomes abnormal, sends a switching control signal to the switch means corresponding to the abnormal information processing device, and A SCSI bus terminator connection control device provided with device disconnection / connection means for disconnecting the SCSI bus derived from the information processing device.

According to the second aspect of the present invention, by taking the above means, the device disconnecting / connecting means is
When a normal / abnormal signal is received from each information processing device, and any one of the information processing devices becomes abnormal at this time,
The switching control signal is sent to the switch means corresponding to the abnormal information processing apparatus, and the information processing apparatus is disconnected, so that the information processing apparatus does not occupy the SCSI bus, and the normal information processing apparatus is not used. Can be appropriately executed, and the operability of the system can be improved.

The invention corresponding to claim 3 has the functions of claim 1 and claim 2 by providing both means of claim 1 and claim 2. The invention corresponding to claim 4 is:
A new SCS is used as the connection control means according to the third aspect.
By adding monitoring means for taking in the I bus and monitoring the state of the SCSI bus,
The state of the SI bus can be easily grasped, and by outputting the state of the bus, for example, the operation state of each information processing device can be easily grasped.

[0017]

FIG. 1 is a block diagram showing an embodiment of a SCSI bus terminator connection control device according to the present invention. In FIG. 1, reference numeral 1 denotes a first information processing apparatus, 2 denotes a second information processing apparatus, and these two apparatuses 1 and 2 are S
And it is connected to the peripheral device 4 via the CSI bus 3 _1, 3 _2.

The first and second information processing apparatuses 1 and 2
Is a function for detecting the on / off state of the power supply from the power supply line via, for example, a voltage dividing element, a function for detecting its own program and other abnormal states, in addition to various data processing functions according to user requests, terminator 5 _1, 5 ₂ of terminating end of the transmission and reception functions and SCSI bus 3 _1, 3 ₂ transmits the power on-off state detection data and abnormality detecting data at a predetermined impedance is provided.

On the other hand, as shown in FIG. 2, the peripheral device 4 is, for example, a hard disk or other SCSI device 11 having necessary functions that can be shared between the information processing devices 1 and 2.
When the terminator 5 ₃ terminating at the ends of the SCSI bus 3 _1, 3 ₂ when needed, and 5 _4, SCSI bus 3
_1, 3 ₂ and Terminator 5 _3, 5 ₄ hard or soft specific switching means 12a selects connection, 12b,
12c, a function of detecting the on / off state of the power supply from a power supply line via, for example, a voltage dividing element, similarly to the information processing apparatuses 1 and 2 (not shown), and its own program and other abnormal states. It has a built-in function to detect and transmit and receive power on / off state detection data and abnormal state detection data.

Reference numeral 6 denotes switch means 12a, 1 of the peripheral device 4.
2b and 12c. The switching control device 6 includes switching means 12a, 12b, 1
Switching control signal lines 7a, 7 for switching control of 2c
b, 7c, and control signal lines 8 ₁ , 8 ₂ , 8 ₃ for receiving power on / off state detection data or abnormal state detection data from the information processing apparatuses 1, 2 and the peripheral device 4.

Next, the operation of the SCSI bus terminator connection control device configured as described above will be described with reference to FIGS. (1) Monitoring of the power supply status of each device (see FIG. 3)
reference).

When the operation is started by turning on the power, the switching control device 6 sets the switch means 12a to 12c to a connected state, for example, as shown in the drawing via the switching control signal lines 7a to 7c, The contents of the memory built in the apparatus are initialized (ST1).

The switching control device 6 in this state, monitors the on and off states of the power supply of each device 1, 2, 4 from the data sent from the control signal line 8 _{1-8 3} every predetermined period ( ST2). Here, if the power-off state of the apparatus is detected for some reason, the next step ST3
Then, it is determined which of the devices 1, 2, and 4 is in the power-off state. For example when the first power of the information processing apparatus 1 is turned off, the SCSI bus 3 ₁ and SCSI bus 3 ₂ has a long distance, the signal on the bus is in a very unstable state.

When the switching control device 6 determines that the power of the first information processing device 1 is off, the switching control device 6 sends a switching control signal to the switching means 12a through a predetermined switching control signal line 7a to perform switching. Execute control. That is, the switch unit 12a, upon receiving the switching control signal, by selecting the terminator 5 ₃ from the SCSI bus 3 ₁ which is derived from the first information processing apparatus 1 of the power-off side, the SCSI bus 3 ₁ and SCSI Bus 3 ₂
S instead of the terminator 5 ₁ connected to the one end portion
CSI connecting bus 3 ₁ Terminator 5 ₃ to the SCSI bus 3 ₁ To take advantage of, performed repositioning terminator for a so-called SCSI bus (ST4, terminator position changing means), by take only SCSI bus 3 ₁ The bus distance is set to the shortest, and the power-on information processing device 2 is continuously operated while maintaining an appropriate bus state.

On the other hand, when the power supply of the peripheral device 4 is turned off, the switch means 7c may be disconnected through the switching control signal line 7c or the state may be maintained (ST5). Also, if the power of the second information processing apparatus 2 is off, and sends the switching control signal to the switch unit 12b through the switching control line 7b, by connecting a terminator 5 ₄ to the other end of the SCSI bus 3 ₁ Then, the connection position of the terminator to the SCSI bus is changed (ST6), the length of the SCSI bus is minimized, and the devices 1 and 4 are continuously operated.

As described above, the switch means 12a-1
After the switching control by 2c, step S is performed at predetermined intervals.
Returning to T2, the same processing is performed again, that is, the power ON / OFF state is determined. At this time, if the power is on, it is determined whether or not recovery processing by the switch means is necessary (ST7). For example, if the power is off before the previous time, and the position of the terminator has not been recovered after that, Then, the corresponding switch means is switched and controlled through the control signal lines 7a to 7c to execute a restoration process for returning the terminator to the original position (ST8).

Therefore, according to the embodiment having such a configuration and processing function, the power supply status of each of the devices 1, 2, and 4 is monitored, and when any of the devices is powered off, the SCS is automatically set.
Since the connection position of the terminator is changed so that the length of the I bus becomes the shortest, the operation error as in the prior art is eliminated,
Further, the influence of noise and the disturbance of the SCSI bus due to the attachment / detachment of the cable are eliminated, and even when the power of the apparatus is turned off, the information processing apparatus which is powered on can properly perform data transmission using the SCSI bus. In addition, when the power of the apparatus is restored, it is possible to detect the power restoration state and automatically restore the state based on the connection position of the terminator. (2) When each device is abnormal (see FIG. 4).

The switching control device 6 includes a switching control signal line 7
The switch means 12a to 12c are set to a connection state as shown in the figure through a to 7c, for example, and the memory contents built in each device are initialized as necessary (ST11). In this state, the process of FIG. 4 is executed at predetermined intervals. That is, the switching control device 6 controls the control signal line 8 ₁
From the data sent from the 8 ₃ monitors the normal or abnormal state of each device 1,2,4 (ST12). When it is determined that the device is abnormal, it is determined which device is abnormal (ST13). Here, when the first information processing apparatus 1 is determined to be abnormal, and sends a switching control signal to the switch unit 12a via the switch control signal lines 7a, disconnecting the switching means 12a from the SCSI bus 3 ₁ process, i.e. After performing the process of disconnecting the information processing device 1 from the bus (ST14, disconnection / connection means), an alarm is output if necessary (ST15) to urge the first information processing device 1 to perform maintenance.

Next, when the peripheral device 4 is abnormal, the switching control device 6 sends a switching control signal to the switching means 12c through the switching control signal line 7c, and the switching means 12c
By turning off the peripheral device 4 from the SCSI bus.
Is disconnected (ST16), an alarm is output (ST16).
17) urge the maintenance of the peripheral device 4;
Even when the second information processing device 2 becomes abnormal, a predetermined process is executed when the first information processing device 1 is abnormal (S
T18, ST19).

Then, when it is determined whether there is an abnormality in the apparatus while repeating predetermined processing at predetermined intervals (ST1).
2), when the apparatus is determined to be normal, and when the switch is in the selected state at the time of an abnormality before the previous cycle (ST20), a switching control signal is sent out, and a recovery connection process is performed by the switch means (ST21), Return to the state.

Therefore, according to the embodiment having the above-described configuration and processing function, the abnormal device is disconnected from the SCSI bus when the device is abnormal, and the terminator built in the peripheral device is connected to the end of the SCSI bus. Since the influence of the SCSI bus due to device abnormality is quickly removed to form a normal bus state, a normal information processing device can properly transmit data using the bus and increase system operability. be able to. (3) Monitoring of the power status of each device and the presence or absence of an abnormality (see FIG. 5).

The switching control device 6 includes a switching control signal line 7
The switch means 12a to 12c are set to a connection state as shown in the figure through a to 7c, for example, and the memory contents in each device are initialized as necessary (ST31).

The switching control device 6 in this state, determines on-off state of the power supply of each device 1, 2, 4 from the data sent from the control signal line 8 ₁ ~8 ₃ (ST
32). If the power of each device 1, 2, 4 is on,
Subsequently, it is determined whether or not each device is abnormal (ST3).
3). When it is determined in step ST32 that the power is off, or when it is determined in step ST33 that the device is abnormal, it is determined whether any device is powered off or any device is abnormal (ST34). Here, when the first information processing apparatus 1 is determined to power off or abnormal, and sends a switching control signal to the switch unit 12a via the switch control signal lines 7a, terminator switch means 12a from the SCSI bus 3 ₁ by connecting to 5 _3, S
In addition to changing the position of the terminator with respect to the CSI bus,
Of the information processing apparatus 1 (ST3)
5, connection control means).

On the other hand, when the power of the peripheral device 4 is turned off or the device is abnormal, a switch control signal is sent to the switch means 12c via the switch control signal line 7c, and the switch means 12c
By turning off the peripheral device 4 from the SCSI bus.
Is disconnected (ST36).

With respect to the power-off of the second information processing apparatus 2 or the apparatus abnormality, predetermined processing is executed in the same manner as the power-off of the first information processing apparatus 1 or the apparatus abnormality (S).
T37).

Then, an abnormality presence / absence state of the apparatus is determined at predetermined intervals (ST33). When it is determined that the apparatus is normal, it is determined whether or not an abnormality has been recovered by maintenance (ST38), and based on the result of the maintenance. If the abnormality has been recovered by the operation, recovery processing for the connection switches 7a to 7c is executed (ST39).

Therefore, according to the embodiment having the above-described configuration and processing function, it is possible to simultaneously achieve the effects obtained when the power is turned off and when the apparatus is abnormal. (Other Embodiments) In this embodiment, as shown in FIG. 6, the switching control unit 6 monitors the state of the SCSI bus by taking in the SCSI bus.

More specifically, the switching control device 6 is set with bus data fetching means for always fetching data to be transmitted on the bus, and judgment reference data for finding a judgment result required by the user in advance. Comparing the data acquired by the capturing means with the judgment reference data,
A bus state determining means for determining a bus state, for example, which device has accessed which device, or what are the contents of the control signal and the bus request signal, and the result of the determination is stored and displayed on a display unit or a printer. And a determination result output means for outputting.

Therefore, according to the above-described embodiment, the status of the system can be easily grasped by sequentially capturing the status of the SCSI bus during the operation of the system and displaying the status on the display unit. It can be used effectively when elucidating the cause of an abnormality at the time of abnormality.

[0040]

As described above, according to the present invention, the following various effects can be obtained. According to the first aspect of the present invention, when the power of the apparatus is turned off, the position of the terminator can be automatically changed to secure an optimal bus state, the influence of noise and the disturbance of the signal of the SCSI bus due to the connection / removal of the cable can be prevented, and the reliability of the system can be reduced. Nature can be secured.

According to the second aspect of the invention, when the information processing apparatus is abnormal, the abnormal side apparatus is disconnected, so that the normal information processing apparatus can properly continue data transmission, and the operability of the system can be ensured.

According to the third aspect of the present invention, when the power of the information processing apparatus is turned off or an abnormality occurs, an appropriate bus state is automatically secured, and the reliability and operability of the system can be secured. According to the fourth aspect of the present invention, by constantly monitoring the state of the bus, the operating state of each device can be easily grasped, and the cause of the abnormality can be clarified.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a SCSI bus terminator connection control device according to the present invention.

FIG. 2 is an internal configuration diagram of a peripheral device of the device of FIG. 1;

FIG. 3 is a flowchart illustrating a processing operation of a SCSI bus terminator connection control device.

FIG. 4 is a flowchart illustrating another processing operation of the SCSI bus terminator connection control device.

FIG. 5 is a flowchart illustrating still another processing operation of the SCSI bus terminator connection control device.

FIG. 6 is a configuration diagram showing another embodiment of the SCSI bus terminator connection control device according to the present invention.

FIG. 7 is a configuration diagram of a conventional SCSI bus terminator connection control device.

[Explanation of symbols]

1, 2, ... The information processing apparatus 3 _1, 3 ₂ ... SCSI bus 4 ... peripheral device 5 ₁ to 5 ₄ ... Terminators 12 a to 12 c ... switch means

Claims (4)

[Claims] 1. A SCSI system comprising: a plurality of information processing devices connected by a SCSI bus; and first terminators built into each information processing device connected to both ends of the SCSI bus.
In the bus terminator connection control device, the SCSI always derived from each of the information processing devices
A device in which a switch means and a second terminator corresponding to the information processing device for electrically connecting the buses are incorporated, and a power supply state of each of the information processing devices is monitored, and the power of one of the information processing devices is turned off. In this case, a switching control signal is sent to the switch means corresponding to the information processing apparatus on the power-off side, and the SCS derived from the information processing apparatus on the power-on side
A SCSI bus terminator connection control device, comprising: terminator position changing means for changing the connection of the end of the I bus to the second terminator instead of the first terminator. 2. A SCSI system comprising a plurality of information processing devices connected by a SCSI bus, and first terminators built into each information processing device connected to both ends of the SCSI bus.
In the bus terminator connection control device, the SCSI always derived from each of the information processing devices
A device in which a switch means and a second terminator corresponding to an information processing device for electrically connecting the buses are incorporated, and an operation state of each of the information processing devices is monitored, and one of the information processing devices becomes abnormal. And a device disconnection / connection means for transmitting a switching control signal to the switch means corresponding to the abnormal information processing apparatus and disconnecting the SCSI bus derived from the abnormal information processing apparatus. A SCSI bus terminator connection control device, comprising: 3. A SCSI comprising a plurality of information processing devices connected by a SCSI bus, and first terminators built into each information processing device connected to both ends of the SCSI bus.
In the bus terminator connection control device, the SCSI always derived from each of the information processing devices
A device incorporating a switch means and a second terminator corresponding to an information processing device for electrically connecting the buses, and a power supply state and an operation state of each of the information processing devices are monitored. When the power is turned off or abnormal, a switching control signal is sent to the switch means corresponding to the information processing apparatus in which the power is turned off or abnormal, and the SCSI bus derived from the information processing apparatus on the power off side or abnormal side. And a connection control means for disconnecting the second terminator and connecting to the second terminator. 4. The SCSI bus terminator connection control device according to claim 3, wherein said connection control means fetches said SCSI bus and sets said S bus to
A SCSI bus terminator connection control device, further comprising monitoring means for monitoring the status of a CSI bus.