JPH035950A - Memory control system for cartridge library device - Google Patents

Abstract

PURPOSE:To guarantee memory contents by once saving the address and old operation information of an area, to which writing is executed, in a specified area and afterwards, executing the writing. CONSTITUTION:When the new operation information are written to a memory 5 (in the case of rewriting), the address and old operation information of the area, to which the information are written, are once saved in specified areas 11 and 12 (the old operation information are read from the area, to which the information are written, of the memory and moved to the specified areas 11 and 12 of the memory). Thus, not only when the unexpected interruption of power supply or rapid voltage fall caused by the service interruption occurs, but also when a defect such as the interruption of DC power supply in a control logic step, etc., is generated, the contents of this memory 5 are guaranteed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a memory control method for a cartridge library device, and in particular to a cartridge suitable for guaranteeing memory contents in the event of an unexpected power outage or power outage. Memory control method for library device [Prior art] Generally, a large number of tape cartridges each containing a magnetic tape recording medium are stored in a storage device, and a robot device automatically selects and stores an arbitrary cartridge. Cartridge library devices are known that transport cartridges from a machine to a recording/reproducing device and automatically record/reproduce them, or vice versa. Automated operations by such robotic devices usually involve recording medium (cartridge)
This is realized by referencing/updating the non-volatile memory that stores the storage position in the storage shelf, the name of the cartridge (volume serial number MSN'), and additional information.

Here, the data to be rewritten in the non-volatile memory includes the above-mentioned cartridge storage position, cartridge name, etc.
The location of the cartridge (for example, when the accessor robot takes out the cartridge and inserts it into the recording/playback device, the location of the cartridge exists).

Cartridge storage shelf → Accessor robot → Recording/playback device) Number of retries for one mechanism (accessor robot, etc.) If the first attempt is successful, the number of retries is set to 1, and the lifespan of each mechanical part and intermittent failure data are recorded to help guide parts replacement and advance maintenance.) Command trace (for a command received from a host CPU, for example, a command to insert a cartridge from a storage shelf into a recording/playback device, the time from the time the command is received to the time the command ends is recorded as a type of maintenance information. (This data is collectively referred to as ``operation information.'') Further, the nonvolatile memory is rewritten, for example, when a cartridge is inserted or removed (increase or decrease), or when the location of the cartridge changes as described above.

Therefore, the memory is one of the important elements for correctly operating this type of cartridge library device, and it is essential to take measures to guarantee the contents of the memory against unexpected power outages and the like. If such measures do not exist,
After the power is restored, there is a risk that a memory read error may occur, the robot may be unable to return the cartridge while it is still in its possession, or the destination of the cartridge that is still inserted in the recording/playback device may become uncertain. Therefore, a one-person restoration is required, which requires a huge amount of time and effort.

As a countermeasure against this problem, conventional methods such as JP-A No. 62-24465
As stated in the publication, when a power outage is detected, data indicating the operating status of the cassette storage unit, playback device, transportation means, etc. at that time is stored in memory, and then writing to the memory is prohibited using hardware. A method is known in which the contents of the memory are protected by setting the memory to the state.

[Problems to be Solved by the Invention] The conventional technology is considered to be effective in power outages where the rate of voltage drop is relatively slow, but it is difficult to solve problems caused by a disconnection immediately before the memory tt111JK terminal (for example, when disconnecting from a 200V AC/5V DC power source). There is no consideration given to failures such as failure of a breaker between memory power supply terminals) or other failures that cause a sudden drop in voltage (such as a failure of a DC breaker). If you are in the middle of
It is also conceivable that the process ends without being written correctly.

Therefore, even after recovery, it is not possible to refer to and judge the memory contents correctly, and when the area is read later, a read error occurs or the contents become uncertain, leading to system downtime. There was a problem in that it required a huge amount of effort to recover.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned problems of the prior art, and to maintain the stored contents of the memory and the cartridge in the correct state (by robot operation) even when the power supply voltage drops not only slowly but also rapidly. An object of the present invention is to provide a memory control method for a cartridge library device that guarantees instruction control information for operating the cartridge library device.

[Means for Solving the Problems] In order to achieve the above object, the memory control method of the cartridge library device of the present invention includes a storage mechanism for a plurality of cartridges and an accessor robot that selects and transports cartridges between recording and reproducing devices. , a non-volatile memory that stores operational information (for example, cartridge storage position information, cartridge name, and the various additional information mentioned above) that instructs and controls the operation of this accessor robot (including the operation and status of the cartridge 1). of memory, and has 5 features.
When writing new operation information to the memory (at the time of rewriting), the address of the area where the writing is to be performed and the old operation information are temporarily transferred to a specific area (11, 1
2) The old operation information to be saved is read from the area of the memory where the writing is to be performed and moved to the specific area of the memory), and then the writing is performed.

Furthermore, after the old operation information is saved to a specific area, a memory update flag (writing flag) is written to a predetermined area (10) on the memory, and then the new information is saved to the area indicated by the address. The memory update flag is written and then the memory update flag is reset (or a memory update end flag is written in the same area as the memory update flag). This series of processing can be configured as a subroutine on the program to reduce the burden on the higher-level program that issues write instructions.

Note that when the program is run from the beginning when the power is turned on next time, the following processing is performed during initialization processing, etc. First, the memory writing flag in the specific area on the memory is read, and if the flag indicates "not writing", normal processing is performed without doing anything to restore the memory (this normal processing is performed by the library device at the higher level). A state in which it is possible to accept commands from the CPU, a state in which it is waiting for processing from a higher-level CPU, a so-called READY state),
If it is "writing in progress", it is determined that a power outage has occurred during the writing process, and based on the address and old data saved in advance.

The old data is written to the area, the writing flag is reset, and the process returns to normal processing. Also.

The "Writing" flag indicates a read error or the content is "
If it does not correspond to either "Writing" or "R", which is not writing, it is determined that the power was cut off when the "Writing" flag was written, and only the "Writing" flag is reset to proceed to normal processing.

The above-mentioned features include processing during memory writing and processing when power is turned on.

[Effect] The effect based on the above configuration will be explained.

According to the present invention, when writing data to the memory for storing operation information of the accessor robot (when updating data),
Since the old data and its address are saved in a specific area before the update is performed, unexpected power outages or sudden voltage drops may occur during the update.

Even if a situation occurs in which data is not correctly written to the memory, destruction or loss of old data can be prevented and the memory contents can be guaranteed. by this.

When the power is restored, the data in memory can be returned to the state immediately before the power was cut off.

Also, when writing new data to memory, after saving the address and old data in a specific area, during memory update (
Since I configured the side to set the "Writing" flag, write the specified data to the area indicated by the address, and then reset the memory updating flag, the contents of the "memory updating flag" when the primary power is turned on. By checking the
It is possible to determine whether memory writing was performed correctly when the power was turned off, and if it was not written correctly, it is possible to return to the state immediately before the power was turned off by processing to restore old data. Therefore, even if data is not correctly written in the memory when the power is turned off, it can be automatically restored when the power is turned on, so that the contents of the memory will not become uncertain.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a cartridge library device according to an embodiment of the present invention, in which 1 is a cartridge library device, 2 is a host CPU, 3 is a magnetic tape controller (MTC), 4 is a library controller 1 (ALC), 5 is a non-volatile memory (LCM, for example, a memory backed up by a battery or a capacitor, which guarantees that stored data will not be lost even in the event of a power outage), 6 is an accessor robot control device (ADtJ), and 7 is a cartridge storage Tank, 8
9 is an accessor robot (AC), and 9 is a magnetic tape unit (MTU).

The upper CPU 2 requests the library control unit (ALC) 4 to transfer the selected cartridge in the cartridge storage IflI 7 to the designated magnetic tape control unit (MTU) 9.
When a command to mount the cartridge is received, the ALC 4 refers to the non-volatile memory (LCM) 5, checks the cartridge storage position, and instructs the robot control unit (ADU) 6 to mount the cartridge.
' ADU6 issues a command to mount on tJ9,
The accessor robot 8 is started, the cartridge is taken out from a predetermined position, and the cartridge is mounted on the MTU 9.

At the same time, the ALC 4 stores in the LCM 5 additional information indicating that the cartridge is moving. In this way, the operation continues while the status of each cartridge and the status of the 808 are reflected on the LCM 5 at any time.

FIG. 2 is a simplified diagram showing the storage contents of the LCM 5 described above, which has areas 51 and 52.

Area 51 contains cartridges and accessor robot AC8.
The cartridge/robot information section manages the status of the robot, and stores various kinds of instruction/control/operation information data described in FIG. 1 and [Prior Art] above. Area 52 is a data save area provided as a feature of this embodiment.
The data save area 52 includes an area 10.1 which indicates a writing flag (memory update flag) in code, and an area 11.1 which saves the write address. It also has an area 12 for saving old data. Note that the LCM 5 is made non-volatile by the battery 13. In addition, Fig. 1 shows A
LC4, ADU6. The figure shows a case where there are one each of LCM5°MTC3 and AC8, and four MTU9, but the number of them is not particularly defined.

Next, a method of controlling the data save area 5.2 of the LCM 5 will be explained.

First, when writing to LCM5.

Current contents indicated by the indicated address (old data)
is read from area 51. Next, the read contents and the designated address are written into the old data save area 12 and the access address save area 11, respectively. After that, write a specific code indicating "Writing 1" in the writing flag area.Next.

The specified data (
After writing (cartridge status data, etc.), reset the "writing" flag in area IO.
A series of processing related to writing is completed by writing a write end signal of a specific code indicating that writing is not in progress. Note that since this process is performed every time memory is written, it may be implemented as a subroutine to reduce the burden on the main program. Note that the unit of data to be rewritten (the amount of data written at one time) is for each operation mode.

Next, processing when the power is turned on after the power is turned off will be explained.

When the power is turned on, after performing processing such as self-diagnosis of the device, the following processing is performed once regarding the LCM 5.

First, the writing flag area 10 is read, and if the content code is "not writing", L CM
No processing is performed regarding 5. In other words, it is assumed that the power was not cut off during writing.

Shift to normal processing. If the above area 10 is "writing", it is determined that the power was cut off while writing to the area indicated by the access address save area, and the contents of the old data save area 12 are written to the area indicated by the address. Then, the writing flag area 10 is reset and returned to the state immediately before the power was turned off.) 1) The program moves to normal processing.

Next, the content of the writing flag area 10 is "Writing".
Or, if neither is "Writing in progress", or if a data parity error, etc. is detected when reading the above area, [! It is determined that the power has been cut off while writing the F writing flag j, and since the area to which writing was scheduled has not been accessed, the ``writing flag'' is simply reset and normal processing is started.

In this way, when writing to LCM5, the old data, address, and flag indicating whether writing is in progress are stored, so the next! It is possible to determine whether a power outage has occurred in the past when the power is turned on, and by performing processing to return old data, the contents of the memory can be guaranteed and uncertain data can be eliminated. Therefore, there is no need to restore the memory contents due to a power outage 111, or to store cartridges still held by the robot or cartridges remaining in the MTU 9.
This means that the restoration work can be done automatically within the system without human intervention.

Note that the present invention can be applied not only to cartridge library devices but also to systems using nonvolatile memory.

In addition, re-insertion of new data that could not be written due to a power outage etc. is mainly performed under the control of the host CPU. ), in the middle of ■, i! When the power is turned off, there is no report of ``■'', so after the power is restored, the CPU performs ``■'' to ``■'' again.

Other data (such as cartridge location) is reloaded within the library device.

Furthermore, even if the robot stops midway due to a power outage, etc., the sequence up to that point is stored in the non-volatile memory LCM, so it can be used to resume operation after the power is restored. be done. Since these matters are not directly related to the present invention, they will not be described in detail.

[Effect of the invention] As explained in detail above, according to the present invention.

When rewriting the memory of the operation/instruction information of the accessor robot, etc. that controls cartridge selection and transport, the old information and its address are always saved in a specific area, so there is no need to worry about unexpected power outages or power outages. Of course, if a sudden voltage drop occurs due to
The contents of this memory can be guaranteed even if various failures occur, such as a power outage, and as a result, processing after power is turned on can be performed smoothly and automatically without confusion or errors.
It has excellent effects.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a cartridge library device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the contents of a nonvolatile memory. 1...Cartridge library device, 2゛-°
-h CPU, 3...Magnetic tape control device, 4
...Library control device, 5...Non-volatile memory, 6". -Accessor robot control device, 7...Car I
-Ridge storage shelf, 8...Accessor robot,
9...Magnetic tape device, 10...Writing flag area. 11...Access address save area, 12
... Old data save area, 51 ... Cartridge/robot information department area, 52 ... Data save area. 1st (!1 112 fig.

Claims (1)

[Scope of Claims] 1. A recording and reproducing device that records and reproduces data on a recording medium stored in a cartridge, a cartridge storage mechanism that stores a plurality of cartridges, and a selection method between the cartridge storage mechanism and the recording and reproducing device. A cartridge library device comprising: an accessor robot that transports a loaded cartridge; and a nonvolatile memory that stores operation information that instructs the operation of the accessor robot.
A cartridge library characterized in that, when writing new operational information to the memory, the address of the area where the writing is to be performed and the old operational information are once saved in a specific area, and then the writing is performed. Device memory control method. 2. When writing the new operation information to the memory, after performing the save, a memory update flag is further written to the memory, and then the new operation information is written to the area indicated by the address. 2. The memory control system for a cartridge library apparatus according to claim 1, wherein the memory updating flag is reset after the memory update flag is written.