GB2310059A

GB2310059A - Data storage and back-up in a computer for a printing press

Info

Publication number: GB2310059A
Application number: GB9702385A
Authority: GB
Inventors: Dieter Duschl; Thomas Schlitz
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1996-02-06
Filing date: 1997-02-06
Publication date: 1997-08-13
Anticipated expiration: 2017-02-06
Also published as: GB9702385D0; GB2310059B; FR2744541B1; DE19604127A1; FR2744541A1

Description

2310059 COMPUTER FOR A PRINTING PRESS This invention relates to a computer

for a printing press, particularly for the control station of sheet-fed a printing press.

For controlling printing presses, in particular offset sheet printing presses, computers are increasingly used which are constructed in the fashion of a PC.

Particularly such computers are used in the control station of a printing press. Via a printing press control station, the monitoring or remote control of the most varied components of the press takes place as well as the detection, control and processing of operational data for the individual print orders. To be noted as data in this connection are, for example, order number, customer name, number of impressions, timing, quality, data, etc. However, from a computer within a printing press for service and maintenance purposes as well as for facilitating an analysis of problems in the case of error, permanently arising press data such as particularly the state of a so-called total sheet counter, are sensed. The frequency with which such data are to be detected and stored depends, in this connection, on the rhythm of the press, i.e. on the speed of the press.

From DE 4 229 266 Al, a computer for the control station of a machine, particularly a printing press, is known which is constructed in the nature of a PC and which has two hard disk drives as non-volatile storage media. In normal operation, the storage as well as the retrieval of data takes place only in connection with one hard disk drive. From time to time, for example according to a predetermined programmed time scheme, or triggered by an operative, security copies of the data and data file are made from the first hard disk drive on to the second hard disk drive. Following dropout of the first hard disk drive by means of a start process of the computer (booting) with a special diskette inserted into the diskette drive, which has information readable by means of the programme part stored in the ROM of the computer, the computer is switched over to the second hard disk drive. Further storage or reading processes then take place exclusively in combination with this intact second disk drive.

The computer briefly described above with two hard disk drives, wherein in normal operation, the computer cooperates with one hard disk drive and from time to time security copies (backups) arise on the second hard disk drive, makes possible on dropout of the first hard disk drive a comfortable and to the maximum extent possible unlimited further usage of the computer system. Since it is a question in the storage media of these computers, however, of hard disk drives with a movable read/write head, contact of the read/write head with the hard disk drive surface can arise (head crashes). If, via such a computer system, the detection and storage particularly of machine rhythm dependent data (e.g. periodic store of a count) takes place, then this means that the read/write head of the hard disk drive during the press operation is positioned for very substantial quantities of time on the corresponding tracks or cylinders of the drive. Head crashes and data losses connected therewith will accordingly occur often in these regions.

The present invention aims to provide a computer adapted to avoid the above-noted disadvantages and, in particular, to provide more effective protection against the loss of data arising at short time intervals.

According to the present invention, there is provided a computer for a printing press and including two nonvolatile re-writeable storage media, the computer being adapted to transfer data or data files present on one storage medium on to the other non-volatile re-writeable storage medium, wherein one non-volatile re-writeable storage medium is constructed as a customary hard disk drive and the further storage medium as a nonvolatile, re-writeable storage device having semiconductor components, the storage device having semiconductor components contains at least some of the data or data files of the storage medium constructed as hard disk, whereby by means of programme routines stored and executable in the computer at least from time to time the reading and/or writing of these data or data files takes place exclusively in combination with the storage medium having semiconductor components, and the computer being programmed to carry out storage processes for data or data files on to the storage medium having semiconductor components and on to the hard disk, and adapted during the access-free times, to move the read-write head of the hard disk drive across regions or cylinders of the hard disk.

In the computer according to the invention, a nonvolatile storage medium of the computer is constructed as, in particular, battery buffered RAM, thus a store having at least one semiconductor component in which the data arising are written and can be permanently stored.

Also, access of the computer to predetermined and, in particular, often needed data, takes place via this battery buffered RAM. Furthermore, it can be provided that by means of control routines which can be carried out by the computer, the read/write head during the access-free times determined by the prior switching in of the battery buffered RAM is positioned or moved over several or all of the regions or cylinders of the hard disc. Preferably it can be provided in this connection that the read/write head within the access-free periods of time is positioned on a specially provided region or cylinder of the hard disk with, in particular, test data. Contact of the read/write head with the hard disk accordingly does not lead to an irretrievable loss of data.

By means of the circuitry provided in accordance with the invention, a store, particularly constructed as battery buffered RAM, which contains at least some of the data or data files to be most often read and/or written as well as the deposition of data (back-up) provided from time to time corresponding to the degree of updating on the hard disk, there arise some of the subsequently enumerated advantages. For one, the data security of the computer system against the previously sketched damaging - influenaes should be noted. Because data which is often to be written during the press operation (e.g. the state of a total sheet counter) is written exclusively on the store of the battery buffered RAM, and a bringing up-todate of the data set on the hard disk correspondingly present thereto takes place only from time to time (hourly) or in dependence on given operational conditions (e.g. on booting the computer) it is guaranteed that this sort of data does not go irretrievably lost on disk crashes. Since, in accordance with the invention, it is furthermore provided that the read/write head of the hard disk drive is to be moved during access-free times over a few or several tracks or cylinders of the hard disk, data losses generated by head crashes can be minimised or totally avoided in their effects. The latter case is specifically present if during the access-free time, the read/write head is positioned on a region of the hard disk containing no actual system data and provided extra therefor. Here, in accordance with a further development of the invention, it can furthermore be provided that by means of write and/or read processes of data of this region, a monitoring takes place with respect to damage generated by disk contact.

A further advantage of the construction of the computer in accordance with the invention emerges in that a continuous maintenance or improvement of the real time ability is achieved. Accordingly it is possible to sense certain data which, in particular, arise in dependence on the press speed more often. Frequent detection of certain data, i.e. a continuous updating of certain data conditions facilitates searching for errors in the case of breakdown.

A further advantage of the invention emerges in that possibilities for real time control of the hardware of the non-volatile RAM with correspondingly triggerable reactions are possible. In this connection, it is provided in particular that the functionability of the battery buffered RAM is permanently determined and on any predictable dropout of the battery buffered semiconductor storage medium immediate storage of the data states contained in the buffered store on to the hard disk takes place.

In what follows, there is the explanation of an exemplary functioning embodiment of the invention. The invention is, in this connection, described with respect to a computer which as well as the control processes indicated further hereinbefore for the press additionally also periodically senses and stores the condition of a sheet counter. This periodic interrogation and storage of the state of a sheet counter is, however, here only representative of a plurality of data which permanently are changing during press operation, wherein the time rate with which these data change depends, in particular, on the press speed.

The computer in accordance with the invention has in addition to a hard disk drive a storage medium containing these connected up battery buffered semiconductor components. In this connection, it is a question, for example, of a battery buffered RAM, preferably in CMOS technology, which is known, for example, under the description "silicon disk". These non-volatile, rewriteable semiconductor stores contain, in this connection, at least some data or data files which are used by the programme running on the computer and effecting the control of the press for reading and/or writing processes. In particular, these are data or data files, in which the previously indicated counter state or condition data are described. Data which arise only seldom (for example only at the beginning of a print order or during putting a press into operation) are, in this connection, not written on the silicon disk, but directly on to the hard disk drive or read from there.

is By means of programme routines stored in the computer, it is effected that after defined times, e.g. once per hour, data contained on the silicon disk are stored on the hard disk, thus a back-up of the data present on both of these storage media is carried out. In accordance with the invention, it is provided, in this connection, that first a determination of the current degree of this redundant present data takes place. This can take place in simple fashion by interrogating the data as well as the time of the last data storage. Consequently the data content of more recent dateltime replaces the corresponding data content of earlier date/time.

Since the silicon disk provided in accordance with the invention in particular detects the often arising status of a sheet counter, there arises in accordance with the data given previously, for example an hourly updating of this counter state on the hard disk, i.e. the counter condition is continuously stored once per hour on to the hard disk.

In accordance with the invention, it is further provided that, for example, on each putting into operation of the computer (booting), an updating of the data present on the silicon disk takes place. Also here first a checking of the time/of the date of the corresponding data commands takes place, so that the more current version of the data to be stored receives preference. In particular, it is guaranteed by this measure that, for example, replacement of the data loss generated by the silicon disk is avoided by a corresponding retrieval of the data of the hard disk.

Because it is provided in accordance with the invention to write at least certain data first on the silicon disk or to read it from this, it is guaranteed that the access times for writing or for reading on the hard disk drive are reduced to a defined minimum. If, for example, it is provided to store (to update) only each hour the data arising on the silicon disk (real time) on to the hard disk, then there arises a correspondingly large accessfree period of time. In accordance with the invention, it is provided, in this connection, that by means of programme routines stored in the computer (this can, in particular, be the operating system of the computer), the read and write head of the hard disk drive within these periods of time is moved over predetermined certain or all regions or cylinders of the hard disk drive. It is provided, in this connection, in particular that in the access-free times which arise for the foregoing reasons, the read/write head of the hard disk drive is positioned on at least one predetermined region or cylinder of the hard disk and remains there until the next disk access. With an at least timewise movement of the read/write head over some or all of the regions or cylinders of the hard disk, it is avoided that the read/write head always remains on the same cylinder or region, namely that region where the last disk access took place. It is accordingly avoided that disk crashes often arise in this area and lead to lasting and irreparable data losses. Since, in particular, a continuous updating of the counter state of the sheet counter deposited on the silicon disk as well as on the hard disk takes place, it is avoided that the read/write head positioned in this cylinder or region generates data losses in these tracks. The non-avoidable contact of the read/write head with the hard disk surface distribute themselves accordingly with continuous movement of the read/write head over the entire or over parts of the hard disk surface and accordingly do not lead to a concentration in one region or cylinder.

Within a further advantageous variant embodiment of the invention, it is provided that the read and write head undertakes in combination with the controlling controller as well as the computer during the access-free times in those regions or cylinders in which it is still continues to be positioned in accordance with the invention (parking position), proofing or checking processes. In this connection, it is possible that for short time intervals, always continuously reading processes are carried out and by means of these reading processes it is tested as to whether data loss because of disk crashes has arisen. If, in particular, it is provided to position the read/write head during the access-free periods of time always again over one and the same region or cylinder of the disk, then here likewise test programmes can be carried out on the basis of writing and reading processes. Also these test cycles run, in this connection, within predetermined short time intervals.

If, by means of the previously described reading processes in given regions or cylinders physical defects are detected, then in a further development it can be provided that the corresponding cluster is taken out of the file allocation table thus locking it against further access. In order to avoid that by means of this locking, larger quantities of data would no longer be available, it can furthermore be provided to copy the error-free sectors into a free cluster in this way thus to make them available again. Not copied are only the sector or sectors with a detected physical defect.

In a computer capable of multi tasking, the previously mentioned reading and/or writing data for the purpose of disk checking is possible in such a fashion that this programme receives the lowest priority level. Thereby almost no restriction arises on the carrying out of the programmes customarily provided with correspondingly higher priority levels.

Claims

1. A computer for a printing press and including two non-volatile rewriteable storage media, the computer being adapted to transfer data or data files present on one storage medium on to the other non-volatile rewriteable storage medium, wherein one non-volatile rewriteable storage medium is constructed as a customary hard disk drive and the further storage medium as a nonvolatile, re-writeable storage device having semiconductor components, the storage device having semiconductor components contains at least some of the data or data files of the storage medium constructed as hard disk, whereby by means of programme routines stored and executable in the computer at least from time to time the reading and/or writing of these data or data files takes place exclusively in combination with the storage medium having semiconductor components, and the computer being programmed to carry out storage processes for data or data files on to the storage medium having semiconductor components and on to the hard disk, and adapted during the access-free times, to move the readwrite head of the hard disk drive across regions or cylinders of the hard disk.

2. A computer according to Claim 1 wherein the storage medium having semiconductor components is constructed as battery or accumulator buffered RAM.

3. A computer according to Claim 2 wherein the storage medium having semiconductor elements is constructed as a silicon disk manufactured using CMOS technology.

A computer according to any one of the preceding Claims wherein the read/write head of the drive is movable during the access-free time over all of the regions or cylinders of the hard disk.

5. A computer according to any one of the preceding Claims and adapted to position the read/write head of the hard disk drive during the accessfree time over at least one predetermined region or cylinder of the hard disk.

6. A computer according to any one of the preceding Claims and adapted to transfer data or data files from the storage medium having semiconductor components to the hard disk drive after detecting and checking the state of updating of the latest data file.

is

7. A computer according to any one of the preceding Claims and adapted via the read/write head of the drive during the access-free time, by writing as well as reading information in the regions or cylinders in which the read/write head is positioned, to monitor the hard disk for damage generated by disk contact.

8. A computer for a printing press having a hard disk drive and a nonvolatile semiconductor storage medium and programmed to transfer data from the latter to the former substantially as hereinbefore described.