JPH06195874A - Data recorder - Google Patents

Abstract

PURPOSE:To prevent lacking of data to be recorded during exchanging a tape by performing exchange processing of the tape during recording operation to the tape is stopped in a period during an input data is being written in a buffer memory. CONSTITUTION:A selector 1 successively writes input data Di in a buffer memory 2A, and when the memory 2A is filled up, the selector 1 switches the buffer memory to a buffer memory 2B. After switching is performed, a selector 3 reads out the data Di written in the memory 2A and records it in a tape of a recording and reproducing device 4. Next, the device 4 stands by until the memory 2B is filled up and recording operation of data read out from the memory 2B is started. Thus, since the device 4 repeats recording operation to the tape and a standby every prescribed time, writing in the memory 2A and 2B is continued, then deficit of recorded data at the time of tape exchange can be prevented by exchanging the tape in a standby time of the device 4 in which tape recording operation of the device 4 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recorder,
Particularly, it relates to a data recorder for recording data on a tape such as a magnetic tape.

[0002]

2. Description of the Related Art Various parameters (observation) such as observation of volcanic activity and measurement of specific parameters of the human body such as brain waves often take a long time. Such measurement data is generally
It is converted into digital data and recorded on a recording medium such as a magnetic tape. A DAT or VTR is adopted as a device for performing such recording and reproduction. By the way, the above-mentioned observations and measurements are generally performed in real time, and therefore take a long time, but actual recording on the tape can be performed in a short time, and conversely, the time required to reproduce from the tape is short. The time axis conversion is useful so that can be obtained as real-time data. As a method of performing this time axis conversion, the measurement data converted into a digital signal at a constant sampling frequency is written in a buffer memory at a recording speed of the sampling frequency, and the measurement data read from the buffer memory is read at a rate higher than the sampling frequency. A method of writing on a tape at a high frequency recording speed is adopted. A digital data recorder adopting such a time axis conversion method has already been proposed by the present inventor (Japanese Patent Laid-Open No. 1-149).
See No. 263).

As described above, since the recording of the measurement data on the tape takes a long time, the recording is not completed with one tape, and it is often necessary to record the data over a plurality of tapes. Conventionally, in such a case, when the recording of the currently mounted tape reaches the end, all recording operations are temporarily stopped, the tape is replaced with a new tape, and the next recording is continued. It was

[0004]

As described above, in the conventional data recorder, when the tape needs to be replaced, the operation of the data recorder is temporarily stopped, the tape is replaced, and then the recording operation is resumed. I was trying to do it. Therefore, for the time during tape exchange, the obtained measurement data is completely ignored, recording is not performed on the tape, and the measurement data is discontinuous in time, that is, data is lost. There was a problem of being lost.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a data recorder which does not cause loss of recorded data even during tape exchange.

[0006]

In order to solve the above-mentioned problems, the data recorder according to the present invention is designed so that first data is input.
In a data recorder having a recording function of writing to a buffer memory at a recording speed of, and recording data read from the buffer memory on a tape at a second recording speed that is faster than the first recording speed, the input to the buffer memory. It is configured to include first means for detecting a period during which the recording operation on the tape is stopped within a period during which data is being written and permitting the tape exchange process.

[0007]

According to the present invention, the fact that the input data speed is slower than the recording speed of the recording device on the tape is utilized, but the writing to the buffer memory is continued, but the tape operation of the recording device on the tape is stopped. During this period, tape exchange is allowed to eliminate loss of recorded data during tape exchange.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. First, the configuration and operation of the data recorder having the time axis exchange function will be described with reference to FIG. In this example, a selector 1 that inputs and outputs recorded data (measurement data) Di and reproduced data Do, a buffer memory 2A and 2B, a selector 3 that selects one of the buffer memories 2A and 2B, a recording / reproducing apparatus 4 and the buffer memories 2A and 2B are provided with a writing / reading control unit 5 for controlling writing and reading.

Input data Di is first sequentially written into the buffer memory 2A at the data rate (sampling rate) via the solid line path of the selector 1. When the input data is further written and the buffer memory 2A becomes full (when the storage area is exhausted), the selector 1 is switched to the broken line side. After this switching is performed, the selector 3 forms a broken line path, and the buffer memory 2
The input data written in A is read and recorded on the tape of the recording / reproducing device 4. This recording operation is completed before the buffer memory 2B becomes full.

Since the recording on the tape is generally completed in a short time, the recording / reproducing apparatus 4 waits until the buffer memory 2B becomes full and the recording operation of the data read from the buffer memory 2B is started. During a period in which the data read from the buffer memory 2A via the selector 3 is recorded on the tape, the subsequent input data is sequentially written into the buffer memory 2B via the broken line path of the selector 1. When the buffer memory 2B becomes full, the selector 1 sets the solid line path again, and the data is stored in the buffer memory 2B.
Will be written to A. After that, the selector 3 sets the solid line path, and the data written in the buffer memory 2B is read and recorded on the tape of the recording / reproducing apparatus 4. Recording on the tape may be completed before the buffer memory 2A becomes full, as described above.

As described above, each time the writing of the input data into each buffer memory is completed, the recording / reproducing device 4
The operation of reading the data from the buffer memory that has been completed and recording it on the tape is repeated. As a result, one block of data is recorded on the tape as one block of data. Normally, the recording speed of data on the tape is unique to the recording / reproducing apparatus 4, and is faster than the input data speed.

At the time of reproduction, the recording / reproducing apparatus 4 starts operation, one block of data is reproduced from the tape, and is written in the buffer memory 2A via the broken line of the selector 3. When the buffer memory 2A becomes full, the selector 3 switches and the next block data is reproduced from the tape via the solid line path and written in the buffer memory 2B. After the switching of the selector 3, the data is read from the buffer memory 2A at a speed corresponding to the input data and output via the solid line of the selector 1. When the writing of the next block data to the buffer memory 2B is completed (when it is full), the data read from the tape is again written to the buffer memory 2A via the broken line path of the selector 3. Such a reproducing operation is repeated. At this time, the data speed at the time of reproducing the data from the tape and writing it in the buffer memory is unique to the recording / reproducing apparatus 4, and is faster than the output data speed.

Although two buffer memories 2A and 2B are used in the above description, the number of buffer memories is arbitrary. Further, for easy understanding, the above block data corresponds to each buffer memory. However, if the storage capacity is large, the number of the buffer memory is one, and the storage area is divided into a plurality of areas, and the above-mentioned divided storage area is divided into a plurality of areas. It goes without saying that writing and reading control may be performed as described above.

Data for one buffer memory is recorded on the tape in a format as shown in FIG. 6, for example. FIG. 6 shows an example in which an R-DAT (rotary head type digital audio tape recorder) is used for the recording / reproducing apparatus. When the tape is run in the direction of the arrow, one block includes a pre-margin area 405, a data area 406, and a post-margin area 407. The pre-margin area 405 is an area that stabilizes tracking during reproduction. The data area 406 is reproduced after traveling in this area and stabilizing the tracking sufficiently.
Actual data is recorded in the data area 406. The post margin area 407 is an area that protects the data area during recording. It is provided so as not to destroy the previous data area 406 at the start of recording of the next block.

The recording / reproducing apparatus 4 simultaneously records / records not only actual data but also the above-mentioned signal for area identification.
Must be playable. When R-DAT is used for recording / reproduction, it is convenient to record a signal for area identification in an area called a subcode area.

Normally, the speed of input data is much slower than the speed of recording data on tape. In other words, record
Recording on the tape of the reproducing device 4 is performed at high speed, and at other times, it is stopped and waits until the buffer memory is full. Therefore, at the time of recording, the slower the input data speed is, the longer the recording / reproducing apparatus 4 stands by, that is, the time during which the tape is stopped without running. The present invention is
This tape stop time is used to enable tape exchange. When the stop time is more than a certain time, tape exchange is allowed, and when it is not more than a certain time, wait until the next tape stop and allow tape exchange. To do. Of course, in this case
Data writing to the buffer memory continues even during tape exchange.

FIG. 1 shows the timing relationship between the write operation of the input data to the buffer memories 2A and 2B and the write operation of the recording / reproducing apparatus 4 on the tape. If the input data rate is Fsi (samples / second) and the capacity of the buffer memory is N (samples), the time T0 (seconds) required to write the input data in the buffer memory is T0 = N / Fsi. If the time required for the recording / reproducing apparatus 4 to record the data of N samples and the pre-margin area and the post-margin area is T1 (seconds), the standby time 2 (seconds) is T2 = T0-T1. . That is, the recording / reproducing device 4 is
The operation of waiting and recording on the tape for the time T1 is repeated every T0. This waiting time T2 is used to allow the tape exchange.

The time for changing the tape can be further extended. Referring to FIG. 2, as described above, the tape exchange can be started during the time T2 from the time t1 after the recording of the previous block is completed to the time t2 when the writing buffer memory 2A is switched to next. As described above, the recording of the contents recorded in the buffer memory 2A onto the tape may be completed before the buffer memory 2B becomes full. Therefore, if the recording timing is shifted to t3 as shown in FIG. Will be expanded from time point t2 to t3. Therefore, if the tape exchange allowable time has the longest time, the tape exchange operation may be started immediately after the time point t1, and the tape exchange operation may be completed within the time of approximately T2 × 2. When the time constraint is severe, the tape exchanging operation is started immediately before the time point t2, and the tape exchanging operation is completed within the time of approximately T2.

FIG. 3 shows a data recording sequence (timing relationship) that enables tape exchange without data loss in the embodiment of the present invention. According to this sequence, it is possible to perform recording with temporal continuity maintained between the data recorded from the buffer memory before the tape exchange is started and the data recorded from the buffer memory after the tape exchange. Further, FIG. 4 shows a flowchart of the operation and processing procedure in the embodiment shown in FIG. Referring to FIGS. 3 and 4, it is determined whether there is a tape exchange request (step S1), and if there is a request, it is determined whether the request is within the tape exchange allowable time (step S1). S2) If it is the tape exchange allowable time, the tape exchange is started at the time t10 (step S3). Step S2
If it is determined that the tape exchange allowable time is not reached, the recording of one block on the tape is completed and the tape exchange allowable time is reached (step S6), and the process returns to step S2. At this time, the writing of the input data is continuously continued. The tape may be replaced manually by a person or automatically by using a robot. The new tape shall be a new tape that is unused, new, or used, and rewound to the beginning.

When the replacement with a new tape is completed, one or some of the following processes are preferably performed in order to facilitate control of reproduction. The first processing is, when the recording / reproducing apparatus 4 has an erasing head, for a suitable time or tape length after the tape exchange is completed,
Run the tape in the forward direction to erase the existing record,
Stop. In the second process, after the tape is exchanged, the tape is run in the forward direction for an appropriate time or tape length, and an identification signal indicating an area to be idle-fed during reproduction is recorded and stopped. The identification signal indicating that it is an area to be idle-fed during reproduction is a signal that causes the recording / reproducing apparatus 4 to behave as if it were an area in which nothing was recorded when this area was reproduced. For example, the control sequence of the recording / reproducing apparatus may be created such that the code indicating the area is recorded with a code other than the pre-margin area, the data area, and the post-margin area, and when the code is detected at the time of reproduction, the tape is idly fed. . The above processing is performed for the following reasons. Generally, there are variations in the winding position of a new tape and the tape winding-up position at the end of rewinding. Therefore, if recording is started immediately after the tape is replaced, recording may start from a point too close to the beginning of the tape, or the previous recording may remain in front, and the newly recorded beginning may not be reproduced correctly. Because there is a fear.

After the tape exchange is completed (time point t20),
The above process and the writing of the input data to the buffer memory to be recorded are waited (time point t30) (step S4), and when the processing is completed, the recording of the data in the buffer memory is started (step S5). If the writing in the corresponding buffer memory is already completed, the recording of the data in the buffer memory is immediately started. This recording operation is performed at time point t40 when the next buffer memory becomes full.
You must finish by the time before. Only when this condition is satisfied, tape exchange without data loss is possible. After that, as usual, each time the writing of the input data to the buffer memory is completed, the data in the buffer memory is recorded on the tape. Due to the above, recording without loss of data during tape exchange, that is, recording in which time continuity is maintained between the data recorded from the buffer memory before the start of tape exchange and the data recorded from the buffer memory after tape exchange It can be performed.

It is clear that at the time of reproduction, the tapes can be exchanged in the same manner as at the time of recording, and the data can be continuously output over a plurality of tapes. However, this requires that the output data rate at the time of reproduction is slow enough to exchange the tape as the input data rate at the time of recording.
The data at the time of reproduction can be written as digital data as continuous data over a plurality of tapes when written on another recording medium such as a semiconductor memory or a floppy disk. It is sufficient to write one block to the buffer memory, read it, and transfer or write it to another recording medium.

[0023]

As described above, the data recorder according to the present invention uses the fact that the input data speed is slower than the recording speed of the recording / reproducing apparatus, but the writing to the buffer memory is continued. Since the tape recording operation of the recording / reproducing apparatus is allowed for the tape exchange during the stopped period, it is possible to record data without loss in the record data at the time of tape exchange.

[Brief description of drawings]

FIG. 1 is a time sequence diagram showing tape exchange timing in a data recorder according to the present invention.

FIG. 2 is a time sequence diagram showing an example in which the tape exchange allowable time is expanded in the data recorder according to the present invention.

FIG. 3 is a time sequence diagram showing a specific tape exchange timing in the data recorder according to the present invention.

FIG. 4 is a flowchart showing an operation processing procedure in the data recorder according to the present invention.

FIG. 5 is a block diagram showing a configuration example of a data recorder according to the present invention.

FIG. 6 is a diagram showing a format on a tape recorded by a data recorder according to the present invention.

[Explanation of symbols]

1, 3 selector 2A, 2B buffer memory 4 recording / reproducing device 5 writing / reading control unit

Claims (4)

[Claims] 1. A recording function for writing input data to a buffer memory at a first recording speed and recording data read from the buffer memory on a tape at a second recording speed higher than the first recording speed. The data recorder comprises first means for permitting a tape exchange process during a period in which the recording operation on the tape is stopped within a period in which the input data is being written in the buffer memory. And a data recorder. 2. A second means for recording the data read from the buffer memory before and after the tape exchange is started, on the tape while maintaining the temporal continuity of the data. The data recorder according to claim 1. 3. After the tape replacement, the tape is run in the forward direction for a predetermined time or tape length,
2. The data recorder according to claim 1, further comprising third means for stopping the tape running after erasing the recorded portion and waiting for the next recording. 4. After the tape replacement, the tape is run in the forward direction for a predetermined time or tape length,
2. The data recorder according to claim 1, further comprising: fourth means for recording a specific identification signal indicating an area to be fed in a blank at the time of reproduction, and then stopping the recording and waiting for the next recording. .