JP3395839B2 - Tape positioning device for magnetic tape unit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a writing operation of a magnetic tape device capable of writing in only one direction from a target position on a magnetic tape loaded in a magnetic tape drive. The present invention relates to a tape positioning device for a magnetic tape device capable of writing data from a normal position to a magnetic tape without destroying prerecorded data due to a failure of positioning at a position.

[0002]

2. Description of the Related Art Conventionally, as a tape positioning device for a magnetic tape device of this type, for example, one having a structure as shown in FIG. This tape positioning device
Magnetic tape 31 loaded in the magnetic tape drive 3
To read / write data from / to the magnetic tape drive 3 according to a command received from the host device 1 and the host device 1 via the magnetic tape control device 2 '. Magnetic tape controller 2'which performs the control command of the magnetic tape 31 and a magnetic tape controller 2'which actually operates the magnetic tape 31 in accordance with the control command issued from the magnetic tape controller 2'to read / write data from / to the magnetic tape 31. It is composed of a tape drive 3.

Of these, the magnetic tape controller 2'includes a first interface circuit 21 and a read / write circuit 2
2, positioning signal transmission circuit 23, second interface circuit 24, MPU bus 25, microprocessor 26,
A control memory 27 and a program recording medium 28 are provided.

The interface circuit 21 is for communicating commands and data with the higher-level device 1, and has a higher-order function by firmware (a program recorded in a program recording medium 28 operated by a microprocessor 26 described later). It has the functions of firmware transfer for communicating with the device 1 and hardware transfer for communicating with the higher-level device 1 by hardware. In the hardware transfer, the host device 1 via the interface circuit 21.
And the read / write circuit 22. As an example, there is a case where firmware transfer is used to transfer control information between the higher-level device 1 and the magnetic tape control device 2, and hardware transfer is used to transfer data to be written on the magnetic tape 31.

The read / write circuit 22 has a function of converting digital data (hereinafter referred to as user data) handled by the higher-level device 1 into a medium format recorded on the magnetic tape 31, and an analog function of the format-converted digital data. It has the function of converting to data. In the format conversion, when writing user data, control information is added to the user data to generate a block pattern for writing on the magnetic tape 31, and an inter-block is generated before the next block pattern is generated. A process of adding a gap (hereinafter referred to as IBG) is performed. It should be noted that, at the time of reading, processing for decomposing the additional information is carried out.

The relationship between the read / write circuit 22 and other circuits will be described. For the interface circuit 21 and the interface circuit 24, the data received from the interface circuit 21 or the interface circuit 24 is converted into digital / analog data. It is converted or analog / digital converted and transferred to the interface circuit 24 or the interface circuit 21. Further, it reports to the positioning signal transmission circuit 23 that the end of the IBG (the end position of the IBG following the block pattern) has been detected. Furthermore, for the firmware, each time the processing of one block pattern is completed (actually, every time the start of the IBG is detected)
Notify and notify the status (normal or abnormal) at the end of reading the block pattern.

The positioning signal sending circuit 23 sends a positioning signal to the magnetic tape drive 3 when there is a positioning signal sending request from the firmware to the magnetic tape drive 3. Regarding the timing of sending the positioning signal, the positioning signal is sent to the interface circuit 24 at an arbitrary position from the start end of the IBG regardless of the operating state of the magnetic tape drive 3.

The interface circuit 24 communicates commands and data between the magnetic tape controller 2'and the magnetic tape drive 3, and has the same function as the interface circuit 21 except that the communication partner is different. Have.

The MPU bus 25 is a bidirectional bus for the microprocessor 26 mounted in the magnetic tape controller 2'to communicate with other circuits.

The microprocessor 26 has a function of operating the entire magnetic tape controller 2'according to the program recorded on the program recording medium 28, and operates while reading the program. The read destination of the program is for control. It may be the memory 27 or the program recording medium 28. However, when reading a program from the control memory 27, it is necessary to copy the program from the program recording medium 28 to the control memory 27 and then read the program.

The control memory 27 stores a copy of the program recorded in the program recording medium 28 and control information necessary for the firmware, and is a readable / writable memory.
(Random Access Memory) is used.

The program recording medium 28 stores a program to be executed by the microprocessor 26 and may be a read-only medium as long as the program recorded by the microprocessor 26 can be read. ROM (Read Onl
y Memory) and FD (Floppy Disk)
And the like are used.

In the tape positioning device for a magnetic tape device having such a configuration, while the magnetic tape drive 3 is in operation, the magnetic tape control device 2'detects the end of the reading / writing process of the block pattern, and then the firmware detects the block pattern. When it is determined that the positioning request is necessary, the positioning signal is transmitted at an arbitrary position of the IBG following the block pattern. The magnetic tape drive 3 stores the position of the positioning signal last received by the magnetic tape control device 2 ', but when the read / write command is received from the magnetic tape control device 2'from the stopped state, the magnetic tape drive 3 is started up. Then, the target position of the magnetic tape 31 loaded in the magnetic tape drive 3 (the magnetic tape drive 3
The positioning completion is reported to the magnetic tape controller 2 ', which indicates that the positioning has been completed at the position where the positioning signal was last received from the magnetic tape controller 2'before the stop. When the magnetic tape controller 2'detects the positioning completion, it starts the read / write operation from that position.

Incidentally, as a well-known technique relating to such tape positioning for a magnetic tape device, there is Japanese Patent Laid-Open No. 57-57.
The magnetic tape control method disclosed in Japanese Patent No. 12407 and the magnetic tape positioning control method disclosed in Japanese Patent Application Laid-Open No. 62-185291 can be used.

[0015]

In the case of the above-described tape positioning device for a magnetic tape device, the first problem is as follows.
When the magnetic tape drive performs the write operation from the stopped state, the data written in advance on the magnetic tape may be mistakenly destroyed when the start-up of the magnetic tape drive fails. . The reason is that a circuit that monitors the completion of positioning of the magnetic tape drive during the startup operation of the magnetic tape drive reports the completion of positioning to the magnetic tape controller, and then some abnormality is detected by the magnetic tape drive or the magnetic tape controller. Even if the magnetic tape is in a state in which writing to the magnetic tape is prohibited, the magnetic tape control device has started the write operation to the magnetic tape drive after receiving the positioning completion report, and therefore, in an abnormal state. It is to write data. In such a case, there is a risk of destroying the data recorded in advance on the magnetic tape.

A second problem is that when a write operation is performed after the magnetic tape drive has operated in the reverse direction, I
The point is that the BG length may exceed the maximum standard value. The reason is that, for example, the IBG length standard is 1.
In a magnetic tape in which an IBG of 6 mm to 3 mm and usually 2 mm is recorded, it is assumed that the recorded IBG length is 3 mm, which is the full standard value, and the magnetic tape device writes 1.2 mm from the positioning completion position of the magnetic tape drive when writing. If the IBG of the length is written, 3 mm
If a positioning signal is sent from the IBG at the half position of the normal standard value of 2 mm from the reverse direction, the IBG is viewed from the medium start side.
This means that the positioning signal is output at the position of 2 mm, and writing from here results in 2 mm + 1.2 mm, which exceeds the maximum value of 3 mm of the standard value.

A third problem is that when a write operation is performed after the magnetic tape drive operates in the reverse direction, I
The point is that the BG length may fall below the minimum standard value. The reason is that, for example, the IBG length standard is 1.
In a magnetic tape in which an IBG of 6 mm to 3 mm and usually 2 mm is recorded, it is assumed that the recorded IBG length is 1.6 mm, which is close to the standard value, and the magnetic tape device writes 0 from the positioning completion position of the magnetic tape drive. ．
Assuming that an IBG with a length of 9 mm is to be written, an IBG with a length of 1.6 mm is normally specified from the reverse direction with a value of 2 mm.
When the positioning signal is sent out at the position of half of the position, the positioning signal comes out at the position of 0.6 mm of IBG as seen from the medium start end side, and if writing is performed from here, 0.6 mm +
This is because it becomes 0.9 mm and the standard value of 1.6 mm is not met.

The present invention has been made to solve such a problem, and its technical problem is that the data previously written on the magnetic tape is written even if the start-up fails during the writing operation of the magnetic tape drive. It is an object of the present invention to provide a tape positioning device for a magnetic tape device, which is not destroyed and the IBG length does not deviate from the standard value.

[0019]

According to the present invention, a magnetic tape drive for operating a loaded magnetic tape to read / write data from / to the magnetic tape, and to read / write data from / to the magnetic tape. And a magnetic tape drive for issuing a control command for reading / writing data from / to the magnetic tape drive according to the command received from the host device. Is a tape positioning device for a magnetic tape device that reads / writes to / from a magnetic tape in accordance with a control command. In the tape positioning device, when the magnetic tape controller completes the read / write process for each block pattern on the magnetic tape, the processed block According to the operation direction of the magnetic tape drive with respect to the magnetic tape drive on the IBG following the pattern Magnetic tape apparatus for a tape positioning apparatus for delivering a positioning signal to start the read / write start position via composed processed from different positioning completion report position is obtained.

Further, according to the present invention, in the tape positioning device for a magnetic tape device, the positioning signal is a block pattern read / write processing end detection when the magnetic tape drive is operating in the forward direction as one direction. When a firmware, which is a program stored in advance in the apparatus to later determine the necessity of a positioning request for the block pattern, determines that a positioning request is required for the block pattern, it indicates a predetermined position. A tape positioning device for a magnetic tape device that is immediately delivered is obtained.

Further, according to the present invention, in the tape positioning device for the magnetic tape device, the positioning signal is a termination signal of the IBG following the block pattern when the magnetic tape drive is operating in the reverse direction opposite to the forward direction. In addition, a tape positioning device for a magnetic tape device can be obtained which is sent out as indicating a position different from a predetermined position when the medium start end side of the IBG on the magnetic tape is detected.

In addition, according to the present invention, in the tape positioning device for the magnetic tape device, the positioning signal is
A tape positioning device for a magnetic tape device can be obtained in which the read / write start position is changed by changing the sending position according to the forward and reverse operations of the magnetic tape drive.

According to the present invention, on the other hand, in any one of the above-described tape positioning devices for a magnetic tape device, when the magnetic tape drive issues a write request to the magnetic tape drive in a stopped state, finally the magnetic tape control device. A magnetic tape that controls the operation speed of the magnetic tape to be in a steady state at the position of the positioning signal received from the device and sends a positioning completion notification to the magnetic tape control device to the effect that positioning is completed at the position of the positioning signal. A tape positioning device for the device is obtained.

On the other hand, according to the present invention, in any one of the above-described tape positioning devices for a magnetic tape device, the magnetic tape control device receives a positioning completion notification from the magnetic tape drive during the writing operation. For a magnetic tape device that performs a write operation from an arbitrary position from the medium start end side of the IBG in consideration of which position from the medium start end side of the IBG was last sent to the magnetic tape drive. A tape positioning device is obtained.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION A tape positioning device for a magnetic tape device according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the basic construction of a tape positioning device for a magnetic tape device according to an embodiment of the present invention. Also in the case of this tape positioning device, FIG.
In the same manner as the conventional device shown in FIG. 1, the host device 1 for issuing a data read / write command to the magnetic tape 31 loaded in the magnetic tape drive 3 via the magnetic tape control device 2, and the host device 1 The magnetic tape controller 2 which issues a control command for reading / writing data to the magnetic tape drive 3 according to the received command, and the magnetic tape 31 is actually operated according to the control command issued from the magnetic tape controller 2. Magnetic tape 31
However, it is common in that it is composed of a magnetic tape drive 3 for reading / writing data.

However, the magnetic tape controller 2 here is
Magnetic tape 31 loaded in the magnetic tape drive 3
On the other hand, in the writing operation of the magnetic tape device that can write in only one direction from the target position, the magnetic recording from the normal position can be performed without destroying the prerecorded data due to the positioning failure at the target position. A function is built to enable data writing to the tape 31.

That is, the magnetic tape control device 2 here is
Reading of each block pattern on the magnetic tape 31 /
The point where the read / write start position differs from the positioning completion report position through different processing according to the operating direction of the magnetic tape drive 3 with respect to the magnetic tape drive 3 on the IBG following the block pattern processed when the write processing is completed The positioning signal for starting from is sent.

When the magnetic tape drive 3 is operating in the forward direction with the magnetic tape drive 3 as one direction, this positioning signal is used in advance in order to determine the necessity of the positioning request for the block pattern after the completion of reading / writing of the block pattern is detected. Program recording medium 28 in tape controller 2
When the firmware, which is the program recorded (stored) in the disk, determines that a positioning request is required for the block pattern, it is immediately sent out as indicating a predetermined position, but the magnetic tape drive 3 reverses the forward direction. When it is operating in the opposite direction, it is sent as the end of the IBG following the block pattern and a position different from the predetermined position when the medium start end side of the IBG on the magnetic tape 31 is detected. That is, such a positioning signal changes the read / write start position by changing the sending position according to the forward and reverse operations of the magnetic tape drive 3.

Therefore, when the magnetic tape drive 3 issues a write request to the magnetic tape drive 3 in the stopped state, the operating speed of the magnetic tape 31 becomes steady at the position of the positioning signal received from the magnetic tape control device 2 at the end. Then, a positioning completion notification indicating that the positioning is completed is sent to the magnetic tape controller 2 at the position of the positioning signal. Further, when the magnetic tape control device 2 receives the positioning completion notification from the magnetic tape drive 3 indicating that the positioning has been completed during the write operation, the position at which the positioning signal is finally sent to the magnetic tape drive 3 is the IBG medium start end side. The write operation is performed from an arbitrary position from the medium start end side of the IBG in consideration of which position is the position.

In this way, in the writing operation to the magnetic tape 31, a waiting time can be provided from the reception of the positioning completion notification by the magnetic tape drive 3 to the start of the writing to the magnetic tape 31. Further, the write start position on the magnetic tape 31 can be started at a fixed position from the medium start end side of the IBG regardless of whether the previous operation is the forward direction or the reverse direction. Therefore, the magnetic tape drive 3
When the firmware detects any abnormality (such as a hardware abnormality) after detecting the positioning completion notification from the device, or when the write operation is performed from the position of the IBG length that is barely to the standard, the data from the wrong position is It becomes possible to prevent writing.

Specifically, the magnetic tape controller 2
Is a first interface circuit 21, a read / write circuit 22, a positioning signal sending circuit 23, a positioning check circuit 29, a second interface circuit 24, an MPU bus 25, a microprocessor 26, a control memory 27,
Also, it is provided with a program recording medium 28 and is different from the conventional magnetic tape controller 2 in that a positioning check circuit 29 is provided between the positioning signal sending circuit 23 and the second interface circuit 24.

The interface circuit 21 is for communicating commands and data with the higher-level device 1, and is a firmware transfer for communicating with the higher-level device 1 by means of firmware and a hardware for communicating with the higher-level device 1 by hardware. It has a transfer function. In hardware transfer, transfer is performed between the host device 1 and the read / write circuit 22 via the interface circuit 21. Here again, as an example, the case where the firmware transfer is used to transfer the control information between the host device 1 and the magnetic tape control device 2 and the hardware transfer is used to transfer the data to be written to the magnetic tape 31 is cited. To be

The read / write circuit 22 has a function of converting user data handled by the higher-level device 1 into a medium format recorded on the magnetic tape 31, and a function of converting format-converted digital data into analog data. To have. In the format conversion, when writing user data, control information is added to the user data to generate a block pattern for writing on the magnetic tape 31, and the IBG is generated before the next block pattern is generated. Perform processing to add. It should be noted that, at the time of reading, processing for decomposing the additional information is performed in reverse.

The relationship between the read / write circuit 22 and other circuits will now be described. The interface circuit 2
1 or the interface circuit 24, the data received from the interface circuit 21 or the interface circuit 24 is subjected to digital / analog conversion or analog / digital conversion and transferred to the interface circuit 24 or the interface circuit 21. Further, it reports to the positioning signal transmission circuit 23 that the end of the IBG (the end position of the IBG following the block pattern) has been detected. Further, it reports to the positioning check circuit 29 that the start of the IBG (the position of the start of the IBG following the book pattern) and the end have been detected. On the contrary, when the read / write start request is received from the positioning check circuit 29, the read / write circuit 22 starts its operation. In addition, the firmware is notified each time the processing of one block pattern is completed (actually, every time the start of the IBG is detected),
Notify the status (normal or abnormal) at the end of reading the block pattern.

The positioning signal sending circuit 23 sends a positioning signal to the magnetic tape drive 3 when the firmware requests the magnetic tape drive 3 to send a positioning signal. The timing of sending the positioning signal differs depending on the operating state of the magnetic tape drive 3. If the magnetic tape drive 3 is operating in the forward direction as one direction,
When the positioning signal transmission request is issued from the firmware, the positioning signal is immediately transmitted to the positioning check circuit 29. If the operation is in the opposite direction to the one direction, the positioning check circuit 29 is waited for until the detection of the IBG end is reported from the read / write circuit 22 after the positioning signal transmission request is generated from the firmware. A positioning signal is sent to.

The positioning check circuit 29 behaves differently when the magnetic tape drive 3 starts up and when the magnetic tape drive 3 is in a steady running state after rising. When the magnetic tape drive 3 is started up in the forward direction, it waits until a positioning check circuit 29 detects a positioning completion signal at a target position in the magnetic tape drive 3 via the interface circuit 24, and is further preset by the firmware. After waiting for a certain period of time, an operation activation request is issued to the read / write circuit 22. When the magnetic tape drive 3 is started up in the reverse direction, the operation is different from that in the forward direction, and the magnetic tape drive 3 does not wait for the positioning completion signal to the target position, but waits only the time preset by the firmware. An operation activation request is issued to the read / write circuit 22. However, when the positioning completion signal to the target position is detected earlier than the preset time, the operation start request is immediately issued to the read / write circuit 22. or,
When the magnetic tape drive 3 is in a steady running state, the read / write circuit 22 receives a report when the start and end of the IBG are detected and the positioning signal sending circuit 23 receives a positioning signal, and receives a positioning signal. Occasionally, a positioning signal is sent to the interface circuit 24 to notify the firmware of the start and end of the IBG and the positioning signal sending position.

The interface circuit 24 is for communicating commands and data between the magnetic tape controller 2 and the magnetic tape drive 3, and the interface circuit 21.
Compared with, it has the same function except that the communication partner is different.

The MPU bus 25 is used by the magnetic tape controller 2
It is a bidirectional bus for the microprocessor 26 implemented therein to communicate with other circuits.

The microprocessor 26 has a function of operating the entire magnetic tape control device 2 in accordance with a program recorded in the program recording medium 28 and operates while reading the program. The read destination of the program is a control memory. 27 or from the program recording medium 28. However, when reading a program from the control memory 27, it is necessary to copy the program from the program recording medium 28 to the control memory 27 and then read the program.

The control memory 27 stores a copy of the program recorded in the program recording medium 28 and control information necessary for the firmware, and is required to be a readable / writable memory. To use.

The program recording medium 28 stores a program executed by the microprocessor 26, and may be a read-only medium as long as the program recorded by the microprocessor 26 can be read. ROM or FD is used.

The following is a flowchart of the operation of this tape positioning device when the magnetic tape drive 3 is started up as shown in FIG. 2, and the operation process from the start-up of the magnetic tape drive 3 shown in FIG. 3 to the start of reading / writing. Will be described with reference to the flowchart of FIG. 4, the flow chart of the operation processing of the block pattern reading completion shown in FIG. 4, and the flow chart of the operation processing of stopping the magnetic tape drive 3 shown in FIG.

First, the positioning between the magnetic tape controller 2 and the magnetic tape drive 3 will be described. The positioning signal sending circuit 23 of the magnetic tape controller 2 sends a positioning signal to the magnetic tape drive 3 at an arbitrary position via the positioning check circuit 29 and the interface circuit 24. The magnetic tape drive 3 stores the position of the positioning signal last received from the magnetic tape control device 2, and the last stored position when the magnetic tape drive 3 is restarted after the magnetic tape drive 3 is stopped. The positioning processing is executed for the positioning signal transmission position of. When the positioning to the positioning signal sending position is completed, the magnetic tape controller 2 is notified of the positioning completion notification.

Therefore, referring to the block pattern read completion operation process shown in FIG. 4, the magnetic tape drive 3
When the data recorded on the magnetic tape 31 is read by the magnetic tape control device 2 by the read / write circuit 2
2, the block pattern is recognized, and when the reading of the block pattern is completed, the block pattern reading completion report is sent to the firmware to determine whether the block pattern processing is completed (step S1).
As a result, if the block pattern processing is not completed, the operation processing is ended, but if the block pattern processing is completed, it is checked whether the block pattern read by the magnetic tape drive 3 is read after the positioning to the target position is completed. Then, it is determined whether the drive positioning is completed (step S2).

As a result, if the drive positioning is not completed, the operation processing is ended, but if it is completed, the information of the block pattern read by the firmware from the read / write circuit 22 (what kind of block pattern, A block pattern check (step S3) is performed by checking whether or not there is an abnormality, and whether or not a positioning request is required for the magnetic tape drive 3 is determined by whether or not there is a positioning signal transmission request (step S4). . As a result, if there is no transmission request, the operation processing is ended, but if there is a transmission request, the positioning signal is transmitted to the positioning signal transmission circuit 23 (step S5).

Next, the positioning check circuit 29 acquires the position of the positioning signal (positioning signal position) and the start / end position of the IBG following the detected block pattern (step S6), and uses the position information for control. It is stored in the memory 27.

In the operation process of completion of reading the block pattern, when the operation state of the magnetic tape drive 3 is the forward direction, the end of the IBG has not been read yet when the positioning signal is transmitted, so the position of the end of the IBG is determined. However, the next process may be executed without waiting until the end of the IBG is detected. Such an operation is repeated while the magnetic tape drive 3 is running and the block patterns are sequentially read, and the control is performed. The positioning signal position and the start / end position of the IBG read from the positioning check circuit 29 stored in the memory 27 are sequentially overwritten and updated.

On the other hand, referring to the operation process of stopping the magnetic tape drive 3 shown in FIG. 5, it is judged whether the firmware detects the stop condition of the magnetic tape drive 3 by the drive stop request (step S1). If there is no request, the operation processing is ended, but if there is a request, the magnetic tape control device 2 performs drive stop processing (step S2) for the magnetic tape drive 3. After the termination process of the magnetic tape drive 3 is completed, the R / W waiting time calculation (step S3) is performed based on the positioning signal sending position and the IBG start / end position stored in the control memory 27,
The result is stored in the control memory 27. Here, the positioning signal transmission position is Psig, and the IBG start end position is Pi.
bgs, the end position of the IBG is Pibge, the speed of the magnetic tape drive 3 (moving speed of the magnetic tape 31) is Vd,
If the R / W waiting time is Twait and the length from the start of the IBG to the position where the read / write processing is restarted is L,
R when the magnetic tape drive 3 is operating in the forward direction
/ W waiting time Twait is Twait = (L-Psig
+ Pibgs) / Vd (hereinafter referred to as equation 1), and the R / W waiting time Twait when operating in the opposite direction is Twait = (L-Psig + Pibg
e) / Vd (hereinafter referred to as Equation 2). However, the initial value of the R / W waiting time is 0.

Next, the operation from the state in which the magnetic tape drive 3 is stopped until the magnetic tape drive 3 is started and the read / write operation for the magnetic tape 31 is started is shown in FIG. The operation processing will be described with reference to the operation processing.

Here, when the magnetic tape control device 2 receives a read / write command from the host device 1, it checks whether the magnetic tape drive 3 is in the start-up direction to determine whether it is a forward start-up command. Is determined (step S1). As a result, if the command is a start-up command in the forward direction, the R / W waiting time stored in the control memory 27 is set in the positioning check circuit 29 to set the R / W waiting time (step S3). After that, the magnetic tape controller 2 executes the start-up command to the magnetic tape drive 3 to start the drive (step S4). If the drive is started in the opposite direction, the R / W wait time is set. After recalculating the R / W waiting time (step S2), the recalculated content is set to the R / W waiting time (step S3), and the magnetic tape controller 2 causes the magnetic tape drive 3 to Drive startup (step S4).

Recalculation of R / W waiting time (step S
In 2), when the magnetic tape drive 3 is started in the reverse direction, a time slightly shorter than the time required for positioning at the target position is set. The details will be shown in a specific example.

On the other hand, referring to the operation process from the start-up of the magnetic tape drive 3 to the start of reading / writing shown in FIG. 3, the firmware issues a start-up command to the magnetic tape drive 3 and then the positioning check circuit 29 causes the firmware to start. Whether or not a read / write activation request has been issued to the read / write circuit 22 is determined by whether or not a read / write activation request has been issued (step S1). If an activation request has been issued, the operation processing is terminated. However, if the start request is not issued and the start request is not issued, it is determined whether or not an abnormality is detected in the magnetic tape control device 2 and the magnetic tape drive 3 (step S2). As a result, if no abnormality is detected, the operation processing is ended, but if an abnormality is detected, a stop request is immediately issued to the magnetic tape drive 3 to perform drive stop processing (step S3) and then operation processing. To end.

Here, since the positioning signal is not sent to the magnetic tape drive 3, the position of the positioning signal and the start / end position of the IBG are not checked. While the abnormality is not detected, the positioning check circuit 29
The above-mentioned check is repeated until a read / write activation request occurs.

Next, regarding the operation of this tape positioning device, a schematic diagram for explaining the operation when the magnetic tape drive 3 operating in the forward direction shown in FIG. 6 is stopped, FIG.
FIG. 8 is a schematic diagram for explaining the operation at the time of starting in the forward direction after performing this operation, and a schematic view for explaining the operation at the time of performing the operation in the opposite direction after performing this operation shown in FIG. 9 is a schematic diagram for explaining a rise time when the magnetic tape drive 3 shown in FIG. 9 is started up in the opposite direction, and an operation when the magnetic tape drive 3 operating in the opposite direction shown in FIG. 10 is stopped. 11 is a schematic diagram for explaining the operation at the time of starting up in the forward direction after performing this operation shown in FIG. 11, and a reverse direction after performing this operation shown in FIG. The operation will be described more specifically with reference to schematic diagrams for explaining the operation.

However, here, the length after reading the block pattern until the reading / writing circuit 22 recognizes the end of the block pattern processing or the end of the IBG is 0.1 mm,
After the block pattern processing is completed, the positioning signal request is generated by the firmware, the length until the positioning signal is sent is 0.4 mm, the distance from the IBG start point where the read / write processing is restarted is 1.0 mm, the magnetic tape It is assumed that the speed of the drive 3 is 2 m / sec.

In the schematic view of FIG. 6, the magnetic tape drive 3
Is moving in the forward direction, tape position is 100.0m
The reading of the block pattern is completed at the position of m and 10
The read / write circuit 22 recognizes the end of the block pattern processing at the position of 0.1 mm (y in step S1 in FIG. 4).
It corresponds to es). At this time, it is assumed that the notification of the positioning completion is received from the magnetic tape drive 3 (corresponding to yes in step S2 in FIG. 4).
And check the status of the read block pattern (Fig. 4
(Corresponding to step S3 of step S4), and it is determined that positioning signal transmission is necessary because the read block pattern is normal (corresponding to yes in step S4 of FIG. 4), and positioning is performed with respect to the positioning signal transmission circuit 23. A signal transmission request (corresponding to step S5 in FIG. 4) is performed, and a positioning signal transmitting position and IBG start / end position are acquired from the positioning check circuit 29 (corresponding to step S6 in FIG. 4).
I do. In FIG. 6, the positioning signal transmission position is 100.5.
mm, the starting position of the IBG is 100.0 mm. Further, since the end position of the IBG has not yet reached at the time of sending the positioning signal, the value of the end position of the IBG will acquire an indefinite value.
It is 9.9 mm.

Next, after the firmware has transmitted the positioning signal at the position of 100.5 mm, it is judged that the magnetic tape drive 3 should be stopped (corresponding to yes in step S1 in FIG. 5), and the magnetic tape is The drive 3 stop processing (corresponding to step S2 in FIG. 5) is performed, and R
/ W waiting time calculation (corresponding to step S3 in FIG. 5) is performed. At this time, since the magnetic tape drive 3 was operating in the forward direction, the R / W waiting time is calculated by the equation 1. The R / W waiting time calculated by Equation 1 is 0.25
It will be m seconds. Finally, the magnetic tape drive 3 is positioned at the position A shown in FIG. 6 to prepare for the next operation.
The operation ends.

A state in which the disc is raised in the forward direction from the position A in FIG. 6 is shown in the schematic diagram of FIG. 7, and a state in which it is raised in the reverse direction is shown in the schematic diagram of FIG.

That is, when the magnetic tape drive 3 is started in the forward direction when stopped at the position A in FIG. 6 (corresponding to yes in step S1 in FIG. 2), R calculated when stopped at the point A / W waiting time 0.25 ms is set in the positioning check circuit 29 (corresponding to step S3 in FIG. 2).
Then, a start-up command (corresponding to step S4 in FIG. 2) is issued to the magnetic tape drive 3. At this time, since the read / write circuit 22 is not activated (corresponding to no in step S1 in FIG. 3), if there is no abnormality in the magnetic tape control device 2 and the magnetic tape drive 3 (no in step S2 in FIG. 3). 7), after issuing a start-up command to the magnetic tape drive 3 (at this point, point A in FIG. 7 is reached) until the completion of positioning is reported (point B in FIG. 7 is reached at this point). ), The abnormality detection is repeated. If an abnormality is detected by this abnormality detection (corresponding to yes in step S2 in FIG. 3), drive stop processing is performed on the magnetic tape drive 3 (step S3 in FIG. 3).
Corresponding to).

As shown in FIG. 7, when the magnetic tape drive 3 is normally started up, as shown in FIG. 7, positioning is performed from the point A to the position of 100.5 mm to which the positioning signal is finally sent. When the positioning is completed at the position of 100.5 mm, the completion of positioning is reported. Since the R / W waiting time of the positioning check circuit 29 is set to 0.25 msec, 0.25 m from the position completion report position.
Wait for the second to elapse (distance: 0.25 msec x 2 m
/Sec=0.5 mm), 101.0 mm position (B in FIG. 7)
When it is positioned at (point), a read / write activation request is issued to the read / write circuit 22 to start the actual read / write operation.

When the magnetic tape drive 3 is started up in the reverse direction when it stops at the position A in FIG. 6 (corresponding to no in step S1 in FIG. 2), the R / W waiting time recalculation (FIG. 2)
(Corresponding to step S2). Therefore, referring to the schematic diagram of FIG. 9, here, when the magnetic tape drive 3 is started up in the reverse direction, the time until the positioning completion report is issued (movement time from point A to point B) ) Is 2
0ms + 20ms + 20ms + 20ms + 10ms = 9
It is 0 ms. Since the IBG length is 2 mm in this specific example, it takes 1 msec to read an IBG of 2 mm at the speed of the magnetic tape device 3 of 2 m / sec. Therefore, here, the R / W waiting time is predicted until the positioning completion report. The IBG read time is subtracted from the time, which is 89 ms (this allows the read / write request to the read / write circuit 22 before the magnetic tape drive 3 reports the positioning completion).

The R / W time obtained by the recalculation is set in the positioning check circuit 29 (corresponding to step S3 in FIG. 2), and the magnetic tape drive 3 is commanded to start up (step in FIG. 2). (Corresponding to S4) is issued. The subsequent operation of the firmware is performed in the same procedure as when operating in the forward direction. As shown in FIG. 8, the operation of the magnetic tape drive 3 when the magnetic tape drive 3 is normally started up is 10 when the position of 88 ms has elapsed from the point A.
The position is 2.5 mm (point B is shown). Therefore, the positioning check circuit 29 makes a read / write activation request to the read / write circuit 22 at this position and starts the actual read / write operation.

Further, referring to the schematic view of FIG. 10, here, when the magnetic tape drive 3 is operating in the reverse direction,
The reading of the block pattern is completed at the tape position of 102.0 mm, and the reading / writing circuit 22 recognizes the completion of the block pattern processing at the position of 101.9 mm (corresponding to yes in step S1 of FIG. 4). At this time, if the positioning completion report is received from the magnetic tape drive 3 (corresponding to yes in step S2 of FIG. 4),
The state of the read block pattern is checked (corresponding to step S3 in FIG. 4), and it is determined that the positioning signal needs to be sent because the read block is normal (corresponding to yes in step S4 in FIG. 4). Then, a positioning signal transmission request (corresponding to step S5 in FIG. 4) is issued to the positioning signal transmission circuit 23. At this time, since the magnetic tape drive 3 is operating in the opposite direction, the positioning signal sending circuit 23 causes the read / write circuit 22 to read the IBG.
Waiting for the detection of the end of the, the positioning signal is transmitted at the position of 99.9 mm. After sending the positioning signal, the firmware obtains the positioning signal sending position (99.9 mm) and the starting / ending position (102.0 / 100.0) of the IBG from the positioning check circuit 29 (corresponding to step S6 in FIG. 4). I do.

Next, the firmware determines that the magnetic tape drive 3 should be stopped after sending the positioning signal at the position of 99.9 mm (step S in FIG. 5).
1)), the magnetic tape drive 3 is stopped (corresponding to step S2 in FIG. 5), and R /
W waiting time calculation (corresponding to step S3 in FIG. 5) is performed. At this time, since the magnetic tape drive 3 was operating in the reverse direction, the R / W waiting time is calculated by the equation 2. The waiting time calculated by Equation 2 is 0.55 ms. The magnetic tape drive 3 is positioned at the position A shown in FIG. 10 to prepare for the next operation, and the operation is completed.

The state of being raised in the forward direction from the position A of FIG. 10 is shown in the schematic diagram of FIG. 11, and the state of being raised in the opposite direction is shown in the schematic diagram of FIG. 12, but regarding these operations, Since the same operations as those described with reference to FIGS. 7 and 8 are performed, the description thereof will be omitted.

FIG. 13 is a flow chart showing another form of operation processing when the magnetic tape drive 3 is started up by the tape positioning device shown in FIG. 1. FIG. 14 shows the magnetic tape drive 3 in reverse during this operation. FIG. 9 is a schematic diagram shown for explaining the operation when the motor is operated in the opposite direction and is stopped and then started up in the opposite direction.

The operation processing here is the same as the operation processing shown in the flowcharts of FIGS. 2 to 5 in the startup processing of the magnetic tape drive 3, and in the flowchart of FIG. However, it is different only in that it is determined whether or not the startup of the magnetic tape drive 3 is an operation in the reverse direction after being stopped by the operation in the reverse direction.

First, the operation of starting the magnetic tape drive 3 in the reverse direction from the state in which the magnetic tape drive 3 operates in the reverse direction and is stopped will be described with reference to the flowchart of FIG.

Here, when the magnetic tape control device 2 receives a read / write command from the higher-level device 1, it checks the start-up direction of the magnetic tape drive 3 to determine whether it is a forward start-up command. Is determined (step S1). As a result, if the start-up is in the reverse direction, it is determined whether the magnetic tape drive 3 is operating in the direction before the start-up by checking whether it is stopped from the forward direction (step S).
In step 2), the R / W waiting time is set to the maximum value if it was operating in the forward direction (step S4), but if it was operating in the reverse direction, the R / W waiting time recalculation ( Perform step S3). Further, it is judged whether or not it is a forward start-up instruction (step S1), and if it is a forward start-up instruction, the R / W waiting time is not changed. Subsequently, the R / W waiting time stored in the control memory 27 is set for the positioning check circuit 29 (step S5), and the magnetic tape controller 2 drives the magnetic tape drive 3 to start up (step S5). Perform S6). As for other operations, the same operations as in the case of the form described above are performed.

Next, the operation of the tape positioning device in this case will be described more specifically with reference to the schematic view of FIG.
However, here, the conditions described in FIGS. 2 to 5 are used for each condition of the specific example.

First, in the case of processing when the magnetic tape drive 3 is stopped in the forward direction and started in the reverse direction, the startup direction of the magnetic tape drive 3 is in the reverse direction (corresponding to no in step S1 in FIG. 13). Since the operation direction before the stop is the forward direction (corresponding to yes in step S2 in FIG. 13), the maximum value is set in the R / W waiting time (corresponding to step S4 in FIG. 13). Here, the maximum value of the R / W waiting time is set to 999.9 seconds. Next, this R / W
A waiting time of 999.9 seconds is set in the positioning check circuit 29 (corresponding to step S5 of FIG. 13), and the magnetic tape drive 3 is started in the opposite direction (FIG. 13).
Corresponding to step S6).

FIG. 14 shows the state of start-up at this time. As can be seen from this, the read / write circuit 22 receives the positioning completion report from the magnetic tape drive 3 at 100.5 mm. Start operation.

Next, in the case of processing when the magnetic tape drive 3 is stopped in the reverse direction and is started in the reverse direction, the start-up direction of the magnetic tape drive 3 is the reverse direction (no in step S1 of FIG. 13). (Corresponding), the operation direction before the stop is the reverse direction (corresponding to no in step S2 in FIG. 13), so the R / W waiting time is recalculated (step S in FIG.
(Corresponding to step 4). The recalculation performed here is shown in FIG.
Since it is the same as the case described in the flowchart of FIG. 5, the R / W waiting time is 89 mm, and this R / W waiting time 89 ms is set in the positioning check circuit 29 (see FIG. 1).
3) (corresponding to step S5 of FIG. 3), and drive startup (corresponding to step S6 of FIG. 13) for starting the magnetic tape drive 3 in the opposite direction is performed. The state of startup at this time is the same as that shown in FIG.

[0075]

As described above, according to the tape positioning device for the magnetic tape device of the present invention, as a first effect, the positioning signal sent to the magnetic tape drive as a control command of the magnetic tape control device is When the magnetic tape drive operates in the forward direction as one direction, the positioning completion report signal is reported at an incorrect position because there is a waiting time from the completion of the positioning report from the magnetic tape drive to the start of writing to the magnetic tape. Even if it happens, it is possible to avoid destroying the data recorded on the magnetic tape. The reason is that since the magnetic tape drive does not write the magnetic tape when the positioning completion report signal is sent, the writing process can be stopped before the writing is started.

The second effect is that by shifting the position of the positioning signal in the forward direction and the backward direction, it is possible to eliminate the deviation of the writing position in the writing operation to the magnetic tape. The reason is that regardless of whether the restart position of the magnetic tape is in the forward or reverse direction,
This is because the calculation is performed so that the BG can be always restarted at a predetermined position from the medium start end side.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a tape positioning device for a magnetic tape device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation process when the magnetic tape drive is started up by the tape positioning device shown in FIG.

FIG. 3 is a flowchart showing an operation process from startup of the magnetic tape drive to start of reading / writing by the tape positioning device shown in FIG.

FIG. 4 is a flowchart showing an operation process of completion of reading a block pattern by the tape positioning device shown in FIG.

5 is a flowchart showing an operation process of stopping the magnetic tape drive by the tape positioning device shown in FIG. 1. FIG.

FIG. 6 is a schematic diagram shown for explaining the operation when the magnetic tape drive operating in the forward direction is stopped by the tape positioning device shown in FIG.

FIG. 7 is a schematic diagram shown for explaining the operation when the system is started up in the forward direction after performing the operation shown in FIG.

FIG. 8 is a schematic diagram shown for explaining the operation when the apparatus is started up in the opposite direction after performing the operation shown in FIG.

FIG. 9 is a schematic diagram for explaining a rise time when the magnetic tape drive is started up in the opposite direction by the tape positioning device shown in FIG.

FIG. 10 is a schematic diagram for explaining the operation when the magnetic tape drive that is operating in the reverse direction is stopped by the tape positioning device shown in FIG.

FIG. 11 is a schematic diagram shown for explaining the operation when the system is started up in the forward direction after performing the operation shown in FIG.

12 is a schematic diagram shown for explaining the operation when the apparatus is started up in the opposite direction after performing the operation shown in FIG.

13 is a flowchart showing another form of operation processing when the magnetic tape drive is started up by the tape positioning device shown in FIG.

FIG. 14 is a schematic diagram for explaining the operation when the magnetic tape drive is operated in the reverse direction in the operation shown in FIG. 13, and is started up in the reverse direction after being stopped.

FIG. 15 is a block diagram showing a basic configuration of a conventional tape positioning device for a magnetic tape device.

[Explanation of symbols]

1 Upper device 2,2 'Magnetic tape controller 3 magnetic tape drive 21, 24 Interface circuit 22 Read / write circuit 23 Positioning signal transmission circuit 25 MPU bus 26 microprocessors 27 Control memory 28 Program recording medium 29 Positioning check circuit 31 magnetic tape

Claims (6)

(57) [Claims] 1. A magnetic tape drive that operates a loaded magnetic tape to read / write data from / to the magnetic tape, and a host device that issues a data read / write command to the magnetic tape. And a magnetic tape control device for issuing a control command for reading / writing the data to the magnetic tape drive in accordance with a command received from the host device, and the magnetic tape drive is further provided with the control command. In the tape positioning device for a magnetic tape device that performs the reading / writing on the magnetic tape according to the above, the magnetic tape control device performs the reading / writing process for each block pattern on the magnetic tape when the read / writing block is processed. The magnetic tape drive for the magnetic tape drive on the interblock gap following the pattern. A tape positioning device for a magnetic tape device, which sends a positioning signal for starting a read / write start position from a position different from a positioning completion report position through different processing depending on the operation direction of the drive. 2. The tape positioning device for a magnetic tape device according to claim 1, wherein the positioning signal is the read / write processing end of the block pattern when the magnetic tape drive is operating in the forward direction as one direction. After the detection, the firmware, which is a program stored in advance in the apparatus to determine the necessity of the positioning request for the block pattern, indicates a predetermined position when the firmware determines that the positioning request is required for the block pattern. A tape positioning device for a magnetic tape device, which is immediately sent as. 3. The tape positioning device for a magnetic tape device according to claim 2, wherein the positioning signal follows the block pattern when the magnetic tape drive is operating in a reverse direction opposite to the forward direction. For a magnetic tape device, which is the end of the inter-block gap and is sent as a position different from the predetermined position when the medium start end side of the inter-block gap on the magnetic tape is detected. Tape positioning device. 4. The tape positioning device for a magnetic tape device according to claim 3, wherein the positioning signal is read / written by changing a sending position in accordance with a forward operation and a backward operation of the magnetic tape drive. A tape positioning device for a magnetic tape device, characterized in that the position is changed. 5. The tape positioning device for a magnetic tape device according to any one of claims 1 to 4, wherein when the magnetic tape drive issues a write request to the magnetic tape drive in a stopped state, finally. The magnetic tape is controlled so that the operating speed of the magnetic tape becomes a steady state at the position of the positioning signal received from the magnetic tape control device, and a positioning completion notification indicating that the positioning is completed is made at the position of the positioning signal. A tape positioning device for a magnetic tape device, which is characterized in that it is sent to a control device. 6. The tape positioning device for a magnetic tape device according to claim 1, wherein the magnetic tape control device performs positioning completion indicating that positioning is completed from the magnetic tape drive during a writing operation. Upon receiving the notification, in consideration of which position from the medium start end side of the inter block gap the position at which the positioning signal was last sent to the magnetic tape drive was taken into consideration. A tape positioning device for a magnetic tape device, which performs a writing operation from a position.