JP2565529Y2 - Magnetic tape unit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape device for reading data written on a magnetic tape and checking whether the data is correctly written.

[0002]

2. Description of the Related Art In general, data written on a magnetic tape is not always reliable. Therefore, in a conventional magnetic tape device, data is written by running a magnetic tape, and the written data is read and correctly read. Whether or not the data has been written is checked by, for example, a parity check.

[0003]

However, in the method of reading out the write data and checking whether or not the data has been written correctly by, for example, a parity check or the like , the magnetic tape slips and one block is read.
Check if the data in the network is completely lost
However, there is a problem that data reliability is poor at present, and thus there are few systems and users using such a magnetic tape device.

Accordingly, an object of the present invention is to provide a magnetic tape device which can improve the reliability of data written on a magnetic tape.

[0005]

In order to achieve the above object, the present invention provides a block indicating the current block position of a magnetic tape.
It counts the number of locks , reads the write data on the magnetic tape at the time of rewinding after writing is completed, detects an error, and detects the number of blocks counted when the magnetic tape is rewound to its start position,
Original block indicating the block position at the start position of
An error is detected by comparing the value with a number . That is, according to the present invention, in a magnetic tape apparatus for checking the data written for each block on the magnetic tape, together to travel in the forward direction is the direction and the writing direction reading the magnetic tape, a rewind direction opposite and the magnetic tape driving means for running in a direction, the traveling by the magnetic tape drive unit
When the magnetic tape runs normally, the magnetic tape
Counting means for counting the number of blocks indicating the definitive current block position, before the time of unwinding after completion of writing
And it detects an error by reading the write data of the serial magnetic tape, which is counted by the counting means when the magnetic tape is rewound to its starting position
The number of blocks and the block at the start position of the magnetic tape
And an error detecting means for detecting an error by comparing the value with the value of the original number of blocks indicating the lock position .

[0006]

Since the present invention has the above configuration, the write data on the magnetic tape is read out at the time of rewinding after the writing is completed, an error is detected, and the current block position of the magnetic tape is counted, and the magnetic tape is read. When rewinding to the start position, the count value is compared with this count value to check the number of write blocks. Therefore, the write data and the number of write blocks are checked, so that the reliability of the data written on the magnetic tape can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the magnetic tape device according to the present invention, FIG. 2 is an explanatory diagram showing the value of a block counter when writing from a block in the middle of the magnetic tape, and FIG. 6 is a flowchart for explaining the operation of the magnetic tape device.

In FIG. 1, a magnetic tape T includes a motor M
As a result, the vehicle travels in the forward direction (right direction in the figure) in the reading direction and the writing direction, and travels in the direction opposite to the rewinding direction (left direction in the figure). Also, this magnetic tape T has
Data is written for each block via the magnetic head H, and the write data is read. The writing means 1 drives the motor M to move the magnetic tape T in the forward direction, and writes data into the magnetic tape T via the magnetic head H for each block. By driving the motor M, the magnetic tape T runs in the forward direction, and data is read from the magnetic tape T via the magnetic head H for each block.

The block counter 3 counts up the current block position of the magnetic tape T when the magnetic tape T runs in the forward direction under the control of the writing means 1 or the reading means 2. Therefore, as shown in FIG. 1, the start position BOT (Beginning Of Tap) of the magnetic tape
When writing (or reading) from e), the value from the tape start position BOT is counted up by the block counter 3, and when writing is started from an intermediate block as shown in FIG. The position is counted by the block counter 3.

At the time of rewinding after the end of writing, the reading means 2 drives the motor M to cause the magnetic tape T to run in the reverse direction and to transfer data from the magnetic tape T via the magnetic head H for each block. When reading, the block counter 3 counts down the number of blocks when the magnetic tape T runs in the reverse direction.

The error detecting means 4 checks the data read by the reading means 2 at the time of rewinding after completion of the writing by using, for example, parity or the like, and when the magnetic tape T is rewound to the tape start position BOT. An error is detected when the count value of the block counter 3 is not 0. The alarm unit 5 issues an alarm to the user by a display or a buzzer when the error detection unit 4 detects an error. The writing means 1, reading means 2, block counter 3 and error detecting means 4 shown in FIG. 1 can be constituted by software of a microprocessor.
Is stored in the work area of the microprocessor.

Next, the operation of the above embodiment will be described with reference to FIG. First, in step S1, it is determined whether the command is a read command, a write command, a rewind command, or an unload command. In the case of a read command and a write command, the processes shown in steps S2 to S4 are executed. In the case of an unload instruction, steps S5 to S5
The processing shown in S11 is executed.

In the case of a read command and a write command, while the magnetic tape T is traveling in the forward direction, the block counter 3 of the magnetic tape T is counted up (steps S2 and S3), and the process returns to step S1 to return to step S1. Tape T
When the vehicle is traveling in the reverse direction, the block counter 3 of the magnetic tape T is counted down (steps S2 and S2).
4) Return to step S1. Therefore, the block position of the magnetic tape T where the magnetic head H is currently located is detected,
It is memorized.

On the other hand, in the case of the rewind command and the unload command, it is determined whether or not the magnetic tape T is at the start position BOT (step S5). To read the write data. That is, this step S
In No. 6, high-speed rewind processing is not performed. Then, in step S7, it is checked whether or not there is an error in the data read from the reverse direction by, for example, a parity check. If there is no error, the block counter 3 is counted down in step S8 and the process returns to step S5. On the other hand, if an error is detected in step S7, the process branches to step S10, where a warning is issued by the alarm means 5 , and the process proceeds to step S11 to perform rewind or rewind.
Performs the unload operation and ends. In this case, the magnetic tape
Warning that there is an error in the contents recorded in
The user of the magnetic recording device can start recording from the beginning
Redo and perform the same error detection operation again.
You .

When the start position BOT of the magnetic tape T is determined in step S5, it is determined in step S9 whether or not the value of the block counter 3 is "0".
If it is not “0”, the number of write blocks is not normal, so the process proceeds to step S10 to issue a warning, and
Proceed to 11. If the value of the block counter is "0" in step S9, the number of write blocks is normal, and the process directly proceeds to step S11 to perform a rewinding process or an unloading process.

Therefore, according to the above embodiment, when rewinding, the magnetic tape T is run in the reverse direction to read out the write data to check for errors, and when the magnetic tape T runs to the start position BOT, the write block Since it is checked whether the number is normal, the reliability of the write data on the magnetic tape T can be improved.

[0017]

As described above, according to the present invention, at the time of rewinding after completion of writing, data written on the magnetic tape is read out, an error is detected, and the block indicating the current block position of the magnetic tape is read. When the number is counted and the magnetic tape is rewound to its start position, this count value and the block at the start position of the magnetic tape are added.
Since the original value indicating the click position is checked number of write blocks are compared, the magnetic tape slips such as
A write error due to the influence can be reliably detected , and the reliability of data written on the magnetic tape can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a magnetic tape device according to the present invention.

FIG. 2 is an explanatory diagram showing values of a block counter when writing is performed from a block in the middle of a magnetic tape;

FIG. 3 is a flowchart for explaining the operation of the magnetic tape device of FIG. 1;

[Explanation of symbols]

 3 Block counter 4 Error detecting means H Magnetic head M Motor T Magnetic tape

Claims (1)

(57) [Scope of request for utility model registration] 1. A magnetic tape apparatus for checking the data written for each block on the magnetic tape, the direction and the write direction der reading the magnetic tape
That causes travel in the forward direction, and the magnetic tape driving means for running in the opposite direction is a rewinding direction, the magnetic tape travels by the magnetic tape drive unit
If the traveled normally, counting means for counting the number of blocks indicating the current block position in said magnetic tape, and detects an error when rewinding After writing the read write data of the magnetic tape, the <br/> The number of blocks counted by the counting means when the magnetic tape is rewound to its start position,
The original block position at the start of the tape
A magnetic tape device comprising: an error detection unit that detects an error by comparing the value with the value of the number of blocks .