DE2233163A1 - METHOD FOR SERIAL RECORDING OF DATA ON AND REPRODUCTION FROM A MAGNETIZABLE RECORDING MEDIUM - Google Patents

Description

Method for the serial recording of data on and to their Playback from a magnetizable recording medium.

The invention relates to a method for the serial recording of Data on and for their reproduction from a magnetizable recording medium with a clock and a data track, although the recording is under the control of one Clock generator, the query with the assistance of one acted upon by the clock track Counter, as well as with a buffer assigned to the data track Storage, via the Cie parallel @ncoming D .-- e serial or the serial data perallel removb @ r as well as a facility to carry out this procedure.

Institutions that work according to such a procedure a buffer memory for serial reproduction of data pending in parallel and vice versa versa, a clock generator delivering a clock frequency, one associated with the clock track Counter and a magnetizable recording medium with a clock and a Data track on, the clock track clocks cen called counter, its status, if by means of a specific reference mark on the recording medium to its zero position is brought, @ the position number is constantly displayed along the scanning coordinate, so that each piece of information scanned in the data track can be identified cf.

"Taschenbuch der Nachrichtenverarbeitung", K. Steinbuch, Springer-Verlag, 1962, Sun 606.

If magnetic tapes are used as recording media, they are special Take precautions to ensure proper signal recording and playback To ensure, for example, no dust particles may be used when recording signals are located between the tape and the write head, the tape must be as straight as possible on the write head and in particular prevent fluttering. Besides these mechanical There are also great demands on electrical interference immunity, so that extensive electrical interference suppression measures have to be taken so that through so-called stray electrical impulses no falsification of the data recording takes place.

Because of these high requirements, such tape storage devices have So far, it has hardly been used as a data storage device for controlling work machines. Apart from the rough workshop operation, workshops are known the so-called electrical atmosphere through the variety of electromagnetic and electrical Heavily contaminated star power lines, electromagnets and motors generating fields, however, through the latter, through the constant switching on, off and over, numerous stray Pulses are generated, which at least partly in addition to the desired information with recorded on the tape, so that an accurate information transfer is not guaranteed. This is to create an electronic interference suppression only possible with a great deal of effort but not economically viable.

The invention is based on the object of a new method so-: ie a device for carrying out the method for recording information on and for their playback from a magnetic tape to create the lower requirements @ls so far on the mechanical design of the components and in particular as far as possible insusceptible to stray impulses is with little technical effort.

Based on the c-et procedure mentioned at the beginning and the fact that with regard to the area of application, recording and Playback times are portable, this object is achieved according to the invention by that the individual clocks and the discrete data each as a pulse train he pulse frequency Record in separate tracks and record the bars in the bar track intermittently can be recorded with a duty cycle of e.g.: 2, and that for fle playback the dates each first et: -a in the middle determined by counting the individual impulses a pulse group scanned on the clock track is decided that a clock is present, so a signal from the data track has to be taken over, for which Reproducing a data signal a predetermined minimum number of times in the data track recorded th pulses is required bil For example, if a pulse frequency of U kHZ and a clock release of 20 msec is selected, see above 120 individual pulses are recorded on the clock track during the clock time and, if a data signal is available, 120 individual pulses are recorded synchronously on the data track. This is followed by a pause of in accordance with the pulse duty factor mentioned above 40 sec Instead of a single data signal, a multitude of pulses doho recorded a group of impulses.

This makes it possible, for example, when scanning an item of information only at the 56th and 60th single pulse of the clock track is queried whether by then E.g. at least 20 single impulses exist in the data track years only then decided that otne discrete information is available for the purpose of data output transferred to the buffer memory: ird. Based on this recording process, In the clock track up to 50, in the data track even more incorrect or deformed individual pulses be allowed. On the other hand, it is almost impossible that during the query time in the data track 20 interfering signals emerge one after the other, which are discrete information would represent, although in fact there is none. This is a high level of security magnetic tape recording and playback even under extreme environmental conditions given with relatively little effort, so that now the use of commercially available, cheap tape cassettes and devices in connection with work machines, for example with lathes, becomes possible in the workshop.

From the German Offenlegungsschrift 1 549 068 zar is a method known for recording bit sequences in series on a magnetic tape, in which the Creation of relatively cheap magnetic tape devices for the data to be stored the so-called alternating clock script can be recorded on a single track, with there is a defined magnetization state in every gap between two characters +, and the magnetic tape at a step-by-step operation in these gaps started and stopped: ird.

The O bits ground with a first frequency and the L bits m one times frequency recorded, which is a multiple of the first frequency, so that for example at frequencies of 2000 Hz and 4000 Hz and a band speed of Gcm / s 13 read pulses for the O bit and 26 read pulses for the L bit are recorded will.

Since the data is recorded in a frequency-modulated manner, it can be integrated a sufficiently large signal-to-noise ratio of the read pulses is achieved. However, one is exact belt speed and exact switching times must be adhered to, can only a short glitch can be suppressed, and are used to separate the information selective amplifiers necessary. Furthermore, the clock signal is due to the self-clocking temporal tolerances subject.

A device for performing the method is according to the invention characterized in that the clock generator coupled to the clock track has a AND element, the second input of which is connected to the output of the dual shift register Buffer is connected, is also operatively connected to the data track that a counter is assigned to both the data track and, as is known per se, the clock track is, the output of the data counter and a first output of the clock counter above an AND element is connected to the serial data input of the shift register, its input via an OR element when recording data on tape the clock generator and for data playback from the tape via a second input of the OR element, which leads to an AND element, whose two inputs are connected to the first and a second output of the counter assigned to the clock track are connected, can be acted upon.

The invention is below @nhand one in the drawing or more less schematically illustrated embodiment in the form of a block diagram described in more detail.

In a tape storage device not shown in detail in FIG from here also not shown drive means a magnetic tape 10 to only schematically shown recording heads 11 and 12 passed. The one Take track 13 and a data track 1 @ on iron magnetic tape 10 are also two playback heads 15 and 16 assigned, of which the playback head 15 is the recording track and the playback head 16 scans the data track.

The device is also composed of a dual shift register Buffer memory 21 through which pending parallel to the memory inputs 22 Information via an information output 23 serially and via an information input 25 information entered serially via memory outputs 24 output in parallel under the influence of a pulse frequency of 5 ktiz of a generator 25 onerous switching element 27, which via a line 23 and an OR element 31 den Clock input 29 of the shift register applied. Known as such switch registers a more detailed description is dispensed with.

The information output 23 is connected to the input via a line 3o an AND-Cliedes 32 connected, the other input via a line 33 with the switching element 27 is connected. The line 33 also leads to the recording head -1.

The output 3 of the AND element leads to the recording head 12.

With the playback head 15 is a first output 10 and a time output --- having electronic counter -: 3 and with the playback head 16, only one electronic counter 46 having an output 45 is connected.

The outputs @ 0 and 45 lead to an AND element logic switching element 48, the output of which via a line 49 to the serial information input 25 of the buffer memory 21 leads. The outputs 40 and 41 of the clock track assigned Counters 3 lead to an AND element 50, the output 52 of which via the OR element 31 is connected to the clock input 23 of the buffer memory 21.

All other parts required for the tape storage device to function and assemblies are left north for the sake of clarity.

The effect of the device described is as follows: With When the magnetic tape 10 is put into operation, the pulse frequency supplied by the generator 25 becomes clocked by 6 kHz via the switching element 27 as a clock generator, i.e., each 20 msec released and blocked for 10 msec, i.e. keyed in a ratio of 1: 2, with the release signal supplied as a clock pulse via line 28 to the buffer memory and at the same time the 120 individual pulses via line 33 and write head 11 on the clock track 13 recorded and fed to the AND element 32.

The information to be recorded on the magnetic tape, which is block by block, = .30 via a keyboard or via another assigned to the working machine Memory 51, transferred to the buffer memory via the parallel memory inputs 22 - orden aren, now arrive bit by bit one after the other under the control of the clock pulses also to the AND element is connected to the serial output by the first clock pulse 23 of the buffer memory shifted memory location contain information, so the AND element 32 also releases the data track 1 for the pulse frequency, so that here 120 individual impulses can also be recorded. With renewed release of the clock frequency become the second, third and all subsequent storage locations in the buffer memory queried.

If one of the storage locations does not contain any information, then the recording of the 120 individual pulses on the data track is suppressed. To this Way -; the entire memory content of the buffer memory is transferred to the magnetic tape each bit information in the data track is represented by 120 individual pulses is.

The recorded information is scanned by the playback heads 15 and 16. Here, T.7 is first an item of information via the logic switching element 48 then provided when the clock track 13 clocked counter 43 b to the example So. pulse is applied to the switching element 48 via output 4-o and on the other hand the Counter 16 has counted at least 20 individual pulses of the data track. The information bit is then permanently available via line 49 at the serial data input 25 of the buffer memory 21 at. As soon as the counter 43 registers the Sun pulse, both conditions are on AND element 50 met, so that the clock input via line 52 and the OR element 31 of the buffer memory 24 is applied, whereby the at the serial input 25 still Always pending bit information is transferred to the memory.

As soon as the buffer memory is full, the magnetic tape is queried interrupted and the content of the buffer memory via the parallel outputs 21 e.g. transferred to a memory of the work machine in a manner not shown here.

Only then is the interrogation of the magnetic tape released again.

Patent claims:

Claims (2)

Claims 3 method for the serial recording of data to and for their reproduction from a magnetizable recording medium with a clock and a data track, with the recording under the control a clock generator, the query with the assistance of one acted upon by the clock track Counter takes place, as well as with a buffer memory assigned to the data track the parallel data in serial or the serial data in parallel can be removed, thereby g e k e n n z 2 1 c h n e t that the individual bars and the discrete data partly as a pulse train of a pulse frequency in separate Tracks (13,11) recorded T? Erden and the clocks in the clock track (13) intermittently can be recorded with a duty cycle of e.g. 1: 2, and that for playback of the data in each case only in the middle determined by counting the individual impulses a pulse group scanned on the clock track is decided that a clock is present, so a signal from the data track (14) is to be taken over, for reproducing a data signal a predetermined minimum number of times in the data track recorded pulses is required. 2. Device for performing the method according to claim 1, with a buffer memory for serial reproduction of data pending in parallel and vice versa versa, a clock generator delivering a clock frequency, one of the Tact track assigned counter and a recording medium with a clock and a Data track, characterized by the fact that the one coupled to the clock track (13) Clock generator (27) via an AND element (34), the second input of which is connected to the output (23) of the buffer memory designed as a dual shift register (21) is connected, is also in operative connection with the data track (14), @ that another counter (4-6) the data track (14) is assigned, - its output (45) and a first output (40) of the cycle counter via an AND element (48) with the serial data input (25) of the shift register are connected, the clock input (29) via an OR element (31) in the data recording on tape by the clock generator (27) and in the Data playback from the tape via a second input (52) of the OR element (31), which leads to an AND element (50) whose two inputs are connected to the first and one second output (40, 41) of the counter (43) assigned to the clock track are connected, can be acted upon.