`
`
`(19)
`
`
`
`(12)
`
`(10)
`
`(21)
`(22)
`(43)
`
`
`Federal Republic of Germany
`
`[emblem]
`German Patent Office
`
`Offenlegungsschrift
`[= published patent application]
`DE 197 08 755 A1
`
`Application number:
`Filing date:
`
`Disclosure date:
`
`197 08 755.8
`March 4, 1997
`September 17, 1998
`
`[barcode]
`(51) Int. Cl.6:
`G 06 F 13/12
`G 06 F 3/00
`
`
`
`
`
`
`
`
`(71) Applicant:
`
`Tasler, Michael,
`
`63773 Goldbach, DE
`
`(74) Representative:
`
`Schoppe, F., Grad. Eng. Univ., Patent
`Attorney, 81479 Munich
`
`
`
`(72) Inventor:
` Same as the applicant
`
`
`(56) Documents cited:
`
`EP 06 85 799 A
`
`IBM Technical Disclosure Bulletin, vol. 38
`(No. 05), p. 249;
`National Instruments IEEE 488 and VXI bis
`Control. Catalog 1994, p. 3-188-3-122;
`
`
`
`
`
`
`
`Flexible Interface
`
`The following information is taken from the documents filed by the applicant.
`An examination has been requested in accordance with § 44 of the German Patent Act.
`
`(54)
`
`
` (57) An interface device delivers fast data communication between a host device
`with input/output interfaces and a data transmit/receive device, wherein the
`interface device comprises a processor unit, a memory unit, a first connecting
`device for interfacing the host device with the interface device, and a second
`connecting device for interfacing the interface device with the data transmit/receive
`device. The interface device is configured by means of the processor unit and the
`memory unit in such a way that, when receiving an inquiry from the host device
`through the first connecting device as to the type of device that is connected to said
`host device, irrespective of the type of data transmit/receive device, the interface
`device sends to the host device by way of the first connecting device a signal, which
`signals to the host device that it is communicating with the input/output device.
`[right margin:] DE 197 08 755 A1
`
`
`
`
`
`
`
`
`
`GERMAN FEDERAL GOVERNMENT PRINTING OFFICE BERLIN 07 98 802 038/45/1 23
`
`ZTE (USA) 1013, Page 1
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`

`

`DRAWINGSPAGE2
`
`Number: DE 197 08 755 Al
`Int. CL.°:
`G 06 F 13/12
`Disclosure date: September 17, 1998
`TO THE DATA
`TRANSMIT/RECEIVE DEVICE
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`ZTE (USA) 1013, Page 2
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`ZTE (USA) 1013, Page 2
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`
`
`

`

`
`
`Specification
`
`
`
`The present invention relates to the transfer of data
`
`
`and, in particular, to interface devices for communication
`between a computer or host device and a data transmit/receive
`device, from which data are to be acquired or with which
`communication is to take place.
`
`Existing data acquisition systems for computers are very
`limited in their area of application. Generally such systems can
`be divided into two groups.
`
`In the first group host devices or computer systems are
`connected by means of an interface to a device, the data of which
`are to be acquired. The interfaces of this group are typically
`standard interfaces, which can be used with a variety of host
`systems, using special driver software. One advantage of such
`interfaces is that they are largely independent of the host device.
`However, there is the disadvantage that they generally require
`very sophisticated drivers, which are fault-prone and which limit
`data transfer rates between the device, connected to the interface,
`and the host device and vice versa. Furthermore, it is often very
`difficult to implement such interfaces for portable systems; and
`they offer few possibilities for adaptation, with the result that
`such systems exhibit little flexibility.
`
`The devices, from which data are to be acquired, cover the
`entire spectrum of electrical engineering. Hence, in a typical
`scenario it is assumed that a customer, who runs, for example, a
`diagnostic radiology system in the medical technology sector,
`reports a fault. Then a service technician of the system
`manufacturer will go to the customer and read the system log
`files, generated by the diagnostic radiology system, by means of,
`for example, a portable computer or laptop. Then, if the fault
`cannot be localized or if the fault occurs only intermittently, it
`will be necessary for the service technician to read not only an
`error log file, but also data from the current operation. It is
`apparent that in this case fast data transfer and rapid data analysis
`are necessary.
`
`Another case for using an interface could be, for example,
`when an electronic measuring device, e.g. a multimeter, is
`connected to a computer system, in order to transfer the data,
`measured by the multimeter, to the computer. Especially in the
`case of long-term measurements or when there is a large volume
`of data, it is necessary that the interface allows a high data
`transfer rate.
`
`From these randomly chosen examples it can be seen that
`the applications that are possible with an interface may vary
`widely. Therefore, it is desirable that an interface be so flexible
`that the interface can be used to connect very different kinds of
`electrical or electronic systems to a host device. In order to
`prevent operator error, it is also desirable that a service technician
`does not have to use different interfaces in different ways for
`different applications, but rather that, if possible, a universal
`method for operating the interface be provided for a large
`number of possible applications.
`
`In order to increase the data transfer rates over an interface,
`the approach that was chosen for the second group of interface
`devices was to match individually the interface very closely to
`individual host systems or computer systems. The advantage of
`this solution is that high data transfer rates are possible.
`
`
`DE 197 08 755 A 1
`However, one drawback is that the drivers for the interfaces of
`the second group are very closely matched to a single host
`system, for which reason they generally cannot be used or can be
`used very ineffectively with other host systems. Furthermore,
`such types of interfaces that have the disadvantage that they must
`be mounted inside the computer housing, because they access the
`internal host bus system, in order to achieve maximum data
`transfer rates. Therefore, they generally do not lend themselves to
`portable host systems in the form of laptops have no free internal
`space to plug in an interface card on account of their size that is
`as small as possible.
`
`A solution to this problem is offered by the interface
`devices of the company IOtech (business address: 25971 Cannon
`Road, Cleveland, Ohio 44146, USA). These interface devices are
`suitable for laptops, such as, for example, the WaveBook/512
`model (registered
`trademark). The
`interface devices are
`connected by means of a plug-in card, which is approximately
`the size of a credit card, to the PCMCIA interface, which are
`now routinely provided as a standard in laptops. The plug-in card
`effects a transformation of the PCMCIA interface to an IEEE
`1284 interface, which is known in the art. The said plug-in card
`provides a special printer interface, which is expanded with
`respect to the data transfer rate and which delivers a data transfer
`rate of approximately 2 MB/s, as compared to a rate of
`approximately 1 MB/s for known printer interfaces. The known
`interface device generally consists of a driver component, a
`digital signal processor, a buffer and a hardware module, which
`terminates in a connector, to which the device, the data of which
`are to be acquired, is connected. The driver component is
`connected directly to the expanded printer interface, as a result of
`which the known interface device establishes a connection
`between a computer and the device, the data of which are to be
`acquired.
`
`In order to work with the said interface, an interface
`specific driver has to be installed in the host device, so that the
`host device can communicate with the digital signal processor of
`the interface card. As already stated above, the driver has to be
`installed on the host device. If the driver is a driver that is
`developed specifically for the host device, it is, indeed, possible
`to achieve a high data transfer rate, but the driver cannot be
`easily installed on a different host system. However, if the driver
`is a general driver, which is as flexible as possible and which can
`be used on many host devices, then compromises must be
`accepted with respect to the data transfer rate.
`
`Especially in the case of an application for multi-tasking
`systems, in which several different tasks, such as, for example,
`data acquisition, data display and editing, are to be performed
`more or less simultaneously, each task is usually assigned a
`certain priority by the host system. A driver, which supports a
`specific task, asks in the central processing system of the host
`device, whether it may have processor resources in order to do its
`task. Depending on the respective priority assignment method
`and depending on the implementation of the driver, a specific
`task is allotted a certain percentage of the processor resources in
`defined time slots. There is a conflict, if one or more drivers are
`implemented in such a way that they have the highest priority by
`default. That is, they are incompatible, as is the case in many
`practical applications. Hence, it may occur that both drivers are
`set to have the highest priority, an aspect that in the worst case
`may even result in a system crash.
`
`
`
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`ZTE (USA) 1013, Page 3
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`

`

`DE 197 08 755 A 1
`
`Preferred exemplary embodiments of the present invention
`The object of the present invention to provide an interface
`
`will be explained in more detail below with reference to the
`device for communication between a host device and a data
`accompanying drawings. The drawings show in:
`transmit/receive device in such a way that said interface device
`can be used independently of the host device and that makes
`Figure 1 a general block diagram of the interface device
`
`possible a high data transfer rate.
`according to the present invention; and
`
`This engineering object is achieved by means of an
`Figure 2 a detailed block diagram of an interface device
`
`interface device in accordance with claim 1 as well as by means
`according to a preferred exemplary embodiment of the present
`of a method in accordance with claim 12.
`invention.
`
`The present invention is based on the finding that both a
`Figure 1 shows a general block diagram of an interface
`
`high data transfer rate and a host device-independent usability
`device 10, according to the present invention.
`can be achieved if an input/output interface of the host device is
`A first connecting device 12 of the interface device 10 can
`
`used. Said input/output interface is usually present in most
`be connected to a host device (not shown) by means of a host
`commercially available host devices. Input/output interfaces,
`line 11. The first connecting device is connected to both a digital
`which are found in practically all host devices, are, for example,
`signal processor 13 and to a memory 14. Furthermore, the digital
`hard disks interfaces, graphics interfaces or printer interfaces.
`signal processor 13 and the memory 14 are connected to a second
`Since, however, the hard disk interfaces in the common host
`connecting device 15 by means of bi-directional communication
`device that can be, for example, IBM PCs, IBM-compatible PCs,
`lines (shown by means of two directional arrows for all lines).
`Commodore PCs, Apple computers or even workstations, are the
`The second connecting device can be coupled by means of an
`interfaces with the fastest data transfer rate, the hard disk
`output line 16 to a data transmit/receive device, which is
`interface is used in the preferred exemplary embodiment of the
`supposed to receive data from the host device or from which data
`interface device of the present invention. However, other storage
`are to be read, i.e. acquired, and transferred to the host device.
`interfaces, such as, for example, floppy disk drives, CD-ROM
`
`Communication with the host system or host device is
`drives or tape drives, could also be used, in order to implement
`based on known standard access commands, as supported by all
`the interface device in accordance with the present invention.
`known operating systems (for example, DOS, Windows, Unix).
`
`The interface device, according to the present invention,
`Preferably the interface device, according to the present
`comprises a processor unit, a memory unit, a first connecting
`invention, simulates a hard disk with a root directory, the entries
`device for interfacing the host device with the interface device,
`of which are "virtual" files, which can be created for a wide
`and a second connecting device for interfacing the interface
`variety of functions. When the host device system, to which the
`device with the data transmit/receive device. The interface device
`interface device, according to the present invention, is connected,
`is configured by means of the processor unit and the memory
`is booted, and a transmit/receive device is also connected to the
`unit in such a way that the interface device, when receiving an
`interface device 10, typical BIOS routines issue an instruction,
`inquiry from the host device through the first connecting device
`which is known by those skilled in the art as the "INQUIRY"
`as to the type of a device that is connected to the host device,
`instruction, to each input/output interface that is present in the
`sends, irrespective of the type of the data transmit/receive device,
`host device. The digital signal processor 13 will receive this
`to the host device through the first connecting device a signal that
`inquiry by way of the first connecting device and will generate a
`signals to the host device that it is communicating with an
`signal, which is sent to the host device (not shown) again by way
`input/output device. Thus, the interface system, according to the
`of the first connecting device 12 and the host line 11. This signal
`present invention, simulates in terms of both the hardware and
`signals to the host device that, for example, a hard disk drive is
`the software the way, in which a conventional input/output
`connected at the respective interface, to which the INQUIRY
`device functions, preferably that of a hard disk drive. Since the
`instruction was sent. Optionally the host device can send an
`support of hard disks is implemented, according to the standards,
`instruction, known by those skilled in the art as "Test Unit
`in all commercially available host systems, the simulation of a
`Ready", to the interface device that requests more precise details
`hard disk, for example, can achieve independence from the host
`regarding the queried device.
`system that is used. Therefore, the interface device of the present
`
`Irrespective of which transmit/receive device at the output
`invention no longer communicates with the host device or
`line 16 is connected to the second connecting device, the digital
`computer by means of a specially designed driver, but rather by
`signal processor 13 informs the host device that the host device is
`means of a program, which is present in the BIOS system (Basic
`communicating with a hard disk drive. If the host device receives
`Input/Output System) and which is usually adapted precisely to
`the response that a drive is present, then it will now send the
`the specific computer system, on which
`it
`is
`installed.
`request to the interface device 10 to read the boot sequence,
`Consequently the interface device, according to the present
`which in the case of actual hard disks is usually found in the first
`invention, combines the advantages of both groups. On the one
`sectors of the disk. The digital signal processor 13, the operating
`hand, the data communication between the computer and the
`system of which is stored in the memory unit 14, will respond to
`interface takes place by means of a host device-specific BIOS
`this instruction by sending to the host device a virtual boot
`program, which could be regarded as a "device-specific driver".
`sequence, which in the case of actual drives includes the type, the
`On the other hand, the BIOS program, which operates one of the
`starting position and the length of the file allocation table (FAT),
`common input/output interfaces in host systems, is simply
`the number of sectors, etc., as known to those skilled in the art.
`present in all host systems, so that the interface device, according
`to the present invention, is host device-independent.
`
`
`
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`ZTE (USA) 1013, Page 4
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`

`

`DE 197 08 755 A 1
`can have an additional buffer, which is used for purposes of
`When the host device has received these data, it assumes that the
`synchronizing the data transfer from the transmit/receive device
`interface device 10, according
`to a preferred exemplary
`to the interface device 10 and the data transfer from the interface
`embodiment of the present invention, is a hard disk drive. In
`device 10 to the host device.
`reply to an instruction from the host device to display the
`directory of the "virtual" hard disk drive, which is simulated by
`Preferably the buffer is implemented as a fast random access
`the interface device 10 with respect to the host device, the digital
`memory or RAM buffer.
`
`Furthermore, the user can also create from the host device a
`signal processor can respond to the host device in exactly the
`configuration file, the entries of which automatically set and
`same way as a conventional hard disk would, namely by reading,
`control various functions of the interface device 10, on the
`upon request, the file allocation table or FAT on a sector,
`specified in the boot sequence, which is generally the first
`interface device 10, which appears to the host device as a hard
`writable sector, and by transferring it to the host device.
`disk. These settings can be, for example, gain, multiplex or
`Furthermore, it is possible that the FAT is not read until
`sampling rate settings. By creating and editing a configuration
`immediately prior to reading or storing the data of the "virtual"
`file, which is usually a text file, which is simple to understand
`hard disk and not already at initialization.
`with little prior knowledge, the user of the interface device 10
`
`In a preferred exemplary embodiment of the present
`can perform essentially the same operator actions for almost any
`invention, the digital signal processor 13, which does not
`transmit/receive device, which can be coupled by means of the
`necessarily have to be implemented as a digital signal processor,
`line 16 to the second connecting device. As a result, a source of
`but rather may be any other kind of microprocessor, comprises a
`errors that are generated from the fact that a user has to know
`first and a second command interpreter. The first command
`many different command codes for different applications, is
`interpreter carries out the steps, described above, while the
`eliminated. In the case of the interface device 10, according to
`second command
`interpreter carries out
`the
`read/write
`the present invention, it is necessary that the user note the
`assignment to specific functions. If at this point the user wishes
`conventions of the configuration file just once in order to be able
`to read data from the transmit/receive device over the line 16,
`to use the interface device 10 as an interface between a host
`then the host device sends a command, which, for example could
`device and almost any transmit/receive device.
`read "read file xy", to the interface device. As already stated
`
`The option of storing any file in agreed upon formats in the
`above, the interface device appears to the host device as a hard
`memory unit 14 of the interface device 10, taking into
`disk. At this point the second command interpreter of the digital
`consideration the maximum capacity of the memory unit, makes
`signal processor interprets the read command of the host
`it possible to implement any expansions or even completely new
`processor as a data transfer command, by decoding whether "xy"
`functions of the interface device 10 without any loss of time.
`denotes, for example, a "real-time
`input" data file, a
`Even files that can be executed by the host device, such as, for
`"configuration" data file or an executable data file, where in this
`example, batch files or executable files (BAT or EXE files), and
`case the second command interpreter begins to transfer data from
`also help files can be implemented in the interface device, thus
`the transmit/receive device by way of the second connecting
`achieving independence of the interface device 10 from any
`device to the first connecting device and over the line 11 to the
`additional software (with the exception of the BIOS routines) of
`host device.
`the host device. On the one hand, this feature avoids licensing
`
`Preferably the volume of data to be acquired by a data
`and/or registration problems; and, on the other hand, installation
`transmit/receive device is specified in a configuration file,
`of certain routines, which can often be used, such as, for
`described in the following, by the user specifying in the said
`example, an FFT routine, in order to be able to look at acquired
`configuration file that a measurement is to last, for example, five
`time-domain data in the frequency range, is no longer necessary,
`minutes. To the host device the "real-time input" data file then
`since the EXE files are already installed on the interface device
`appears as a file having a length that corresponds to the volume
`10 and appear in the virtual root directory, by means of which the
`of data anticipated in the five minutes. Those skilled in the art
`host device can access all programs that are stored on the
`know that communication between a processor and a hard disk
`interface device 10.
`consists of the processor transferring to the hard disk the numbers
`
`In a preferred exemplary embodiment of the present
`of the blocks or clusters or sectors whose contents it wishes to
`invention, in which the interface device 10 simulates a hard disk
`read. From the FAT the processor knows which information is
`drive to the host device, the interface device is automatically
`contained in which block. Therefore, in this scenario the
`detected and readied for operation as soon as the host system is
`communication between the host device and the interface device
`powered up or booted. This corresponds to the currently
`of the present invention consists of the very fast transfer of block
`increasing and widespread "plug-and-play" standard. The user
`numbers and preferably of block number ranges, because a
`needs no longer to be concerned about installing the interface
`"virtual" "real-time input" file will not be fragmented. If at this
`device 10 on the host device by means of specific drivers, which
`point the host device now wants to read the "real-time input" file,
`have to be loaded, but rather the interface device 10 is
`it transfers a range of block numbers to the interface device,
`automatically readied for operation when the host system is
`whereupon the process is started that data are received by way of
`booted.
`the second connecting device and are sent to the host device by
`
`However, it is obvious to those skilled in the art that the
`way of the first connecting device.
`interface device 10 is not necessarily signed on when the
`
`In addition to the instruction memory for the digital signal
`computer system is turned on, but that a special BIOS routine can
`processor, where in this case said memory comprises the
`also be started on the host device when the computer is running,
`operating system of the digital signal processor and can be
`in order to sign on or "mount" the interface device 10 as an
`implemented as an EPROM or EEPROM, the memory unit 14
`
`
`
`
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`ZTE (USA) 1013, Page 5
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`

`DE 197 08 755 A 1
`a smooth operation of the interface device 10 even in the case of
`additional hard disk. This embodiment is suitable for larger
`workstation systems, which are essentially never turned off,
`time-critical applications in multi-tasking host systems.
`because they perform, for example, mail functions or monitor
`Figure 2 shows a detailed block diagram of an interface device
`processes that run continuously, for example, in a multi-tasking
`10 according to the present invention.
`environment.
`A digital signal processor (DSP) 1300 is, in a way, the heart
`
`
`In the interface device, according to the present invention,
`of the interface device 10. The DSP can be any DSP, where in
`there is an enormous advantage, as can be seen in the exemplary
`this case, however, it is preferred that it has an on-chip random
`embodiment described in the following, in separating the actual
`access memory (RAM) of 20 KB. Certain instruction sets, for
`hardware, which is required for connecting the interface device
`example, can be stored in the random access memory, which is
`10 to the transmit/receive device, from the communication unit,
`already integrated in the DSP. An 80 MHz clock member 1320 is
`which is implemented by means of the digital signal processor
`connected to the DSP 1300, in order to synchronize the DSP.
`13, the memory 14 and the first connecting device 12, because
`The DSP implements a fast Fourier transformation (FFT) in real
`this feature allows a plurality of dissimilar device types to be
`time and also optional data compression for the data to be
`operated in parallel in an identical manner. As a result, many
`transferred from the transmit/receive device to the host device, in
`interface devices 10 can be connected to a host device, which
`order to achieve greater efficiency and to be able to work
`will then sees many different "virtual" hard disks. On the other
`together with host devices, which have smaller memory units.
`hand, any change in the specific hardware, which is symbolized
`
`In the preferred exemplary embodiment of the interface
`by the second connecting device 15, can be implemented in
`device 10 shown in Figure 2, the first connecting device 12 from
`essence without changing the operation of the interface device,
`Figure 1 comprises the following components: an SCSI interface
`according to the present invention. Furthermore, an experienced
`1220 as well as a 50 pin SCSI connector 1240, in order to
`user can intervene at any time on any level of the existing second
`connect to an SCSI interface, which is present in most host
`connecting device by making use of the above mentioned option
`devices or laptops. The SCSI (SCSI = small computer system
`of creating a configuration file or by adding or storing new
`interface) interface 1220 converts the data, received by way of
`program sections for the second connecting device.
`the SCSI connector 1240, into data, understood by the DSP
`
`Furthermore, one important advantage of the interface
`1300, as known by those skilled in the art. Furthermore, the first
`device 10 of the present invention consists of it also enabling
`connecting device 12 comprises an EPP (EPP = enhanced
`extremely high data transfer rates and, in particular, just by the
`parallel port) that has a data rate of approximately 1 MB/s and
`fact that the host device's own BIOS routines, which are
`delivers a more moderate data transfer rate of 1 MB/s in
`optimized for each host device by the manufacturer of the host
`comparison to the data transfer rate of 10 MB/s of the SCSI
`device or BIOS system, are used to exchange data. Furthermore,
`interface. The EPP 1260 is connected to a 25 pin sub-D
`the simulation of a virtual mass storage device allows the data to
`connector 1280 in order to be connected, for example, to a
`be managed and made available in such a way that said data can
`printer interface of a host device. Furthermore, the first
`be transferred directly to other storage media, for example, to an
`connecting device 12 comprises optionally a 25 pin connector
`actual hard disk of the host device without, so to speak,
`1282, which allows 8 digital outputs and 8 digital inputs 1284 to
`intervention of the host device processor. Therefore, the only
`be connected to a host device.
`constraint on long-term data transfer at high speed is set strictly
`
`The second connecting device comprises preferably 8 BNC
`by the speed and the size of the mass storage device of the host
`inputs with calibration relays 1505, a block 1510 with 8 device
`device. This is the case, since the digital signal processor 13
`amplifiers with an overvoltage protection of ± 75 V, where in
`already
`formats
`the data, which are
`read
`in by
`the
`this case this block is connected in turn to 8 sample/hold
`transmit/receive device by way of the second connecting device
`members (sample/hold = S&H) 1515. The calibration relays are
`15, in block sizes that are suitable for a hard disk of the host
`relays that allow a controlled changeover between a test voltage
`device. In this case the data transfer speed is limited only by the
`and a calibration reference voltage. Each sample/hold device is
`mechanical latency of the hard disk system of the host device. At
`connected to a corresponding input of an 8 channel multiplexer
`this point it should be noted that normally data flow from a host
`1520, which feeds its output signals through a programmable
`device must be formatted in blocks in order to be able to write to
`amplifier 1525 into an analog/digital converter (ADC) with 12
`a hard disk and subsequently to be able to read from a hard disk,
`bit and 1.25 MHz 1530 and to the DSP 1300. The ADC 1530 is
`as known to those skilled in the art.
`controlled by means of a 20 bit timer 1535, as known to persons
`
`The said data transfer rate can be increased once again by
`skilled in the art. The programmable amplifier 1525 and the 8
`setting up a direct memory access (DMA) or RAM drive in the
`channel multiplexer 1520 are controlled by means of an amplifier
`host system. As those skilled in the art know, the setting up of a
`channel selection component 1540, which in turn is controlled by
`RAM drive requires processor resources of the host device, for
`the DSP 1300.
`which reason the advantage of writing the data to a hard disk
`The whole interface device 10 is supplied with power by an
`
`drive of the host device and in essence no processor resources are
`external AC/DC converter 1800, which delivers a digital power
`required, is lost.
`supply of + 5 V and is connected to a DC/DC converter 1810,
`
`As already stated above, a data buffer can be implemented
`which can deliver analog power supply voltages of ± 5 V and ±
`in the memory 14. Said data buffer allows the transmit/receive
`15 V, as required for the interface device 10.
`device, which is coupled to the second connecting device, to be
`independent in terms of time from the host device, which is
`connected to the first connecting device. This feature guarantees
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`DE 197 08 755 A 1
`are desirable and widely used, in particular, by mobile service
`Furthermore, the DC/DC converter controls a precision voltage
`technicians. The EPP 1260 with its associated connector 1280
`reference 1820, which controls the 8 BNC inputs 1505 and the
`enables a more moderate data transfer.
`ADC 1530 as well as a digital/analog converter (DAC) 1830,
`
`As already stated above, the power supply to the interface
`which by way of an output amplifier block with 4 output
`device 10 is achieved by means of an external AC/DC adapter,
`amplifiers 1840 and a 9 pin connector 1850 makes possible an
`which has a universal power input (85 to 264 VAC, 47 to 63 Hz).
`analog output directly from the DSP 1300 to an output device,
`Interference suppression satisfies the standards EN 55022, curve
`such as, for example, a printer device or a monitor device, which
`B and FFC, Class B). Furthermore, it is also designed in
`can be connected to the 9 pin connector 1850, so that optimally it
`accordance with international safety regulations (TÜV, UL,
`is possible to monitor the data transferred to the host device or
`CSA). The interface device 10 is externally shielded and
`also, for example, to view an FFT, in order to obtain fast and
`achieves a value of