GB2039198A

GB2039198A - Data display apparatus

Info

Publication number: GB2039198A
Application number: GB7850001A
Authority: GB
Original assignee: Ferranti PLC
Current assignee: Ferranti International PLC
Priority date: 1978-12-27
Filing date: 1978-12-27
Publication date: 1980-07-30
Also published as: GB2039198B; DE2951448A1

Abstract

Data display apparatus comprises sequencing means 20, 21 providing pulses to switching means S1 ... S10, to control a sequence of output signals from a common output P for a number of associated data sources, e.g. diodes D1 ... D10, comprising temperature- measuring means, such sequence being used to drive a display unit, e.g. an oscilloscope 10, to provide a bar-graph display of the data signals. Only a single communication channel 24 is required between the apparatus and the oscilloscope which is synchronized with the sequencing means 20, 21. The amplitude of the bar-graph and the position of the datum line (offset) are determined by the values of the resistances in the amplifier circuits A1, A2. <IMAGE>

Description

SPECIFICATION Data display apparatus This invention relates to data display apparatus, and in particular to such apparatus each to drive in an appropriate manner an associated display unit, in response to data signals to be supplied to the apparatus by a plurality of associated sources, each associated source comprising measuring means, so that there is displayed by the unit representations of the magnitudes of the different instantaneous measurements determined by the sources, and represented by the data signals.

It is an object of the present invention to provide a novel and advantageous construction for such data display apparatus.

According to the present invention data display apparatus to drive in an appropriate manner an associated display unit, the associated display unit having timing means to control the manner of operation of the display unit so that the display unit has a uniformly repetitive active response time determined by the timing means, the operation of the data display apparatus partially being in response to data signals supplied thereto by a plurality of associated sources, each associated source comprising measuring means, and including a detector to be energised by electrical supply means, the magnitude of a parameter of each data signal representing the magnitude of an instantaneous measurement determined by the source providing the data signal, and the data display apparatus includes switching means, having a plurality of switches, arranged such that each data source is to be connected individually to a switch, and different data sources are to be connected to different switches, the switches to be actuated in response to pulses from sequencing means of the data display apparatus, the sequencing means to be connected to the timing means of the associated display unit to receive signals therefrom, so that the manner of operation of the sequencing means is synchronised with the manner of operation of the timing means, and a common output for the data display apparatus is provided between the switching means and the associated display unit, in response both to the pulses from the sequencing means to the switching means, and to each of a plurality of relevant data signals received by the apparatus, the apparatus is to provide, from the common output thereof, a plurality of output signals to drive the associated display unit in the appropriate manner, each output signal being provided individually in response to a relevant data signal, and at least corresponding to the relevant data signal, the magnitude of a parameter of each output signal representing the magnitude of the instantaneous measurement represented by the corresponding relevant data signal, the arrangement being such that each output signal is to be provided individually by the data display apparatus to the associated display unit in a sampling time within a uniformly repetitive active response time of the associated display unit, with different such output signals, in response to different relevant data signals, from different ones of the plurality of associated data sources, being provided, in a predetermined sequence, in different sampling times, in each of the uniformily repetitive active response times, output signals in corresponding sampling times in each of the consecutive uniformly repetitive active response times being in response to relevant data signals from the same source, the predetermined sequence of output signals from the apparatus, within each of the consecutive uniformly repetitive active response times, being determined by the sequencing means, and being synchronised with the signals from the timing means of the associated display unit to the switching means.

Thus, there can be displayed by the associated display unit, in each of the consecutive uniformly repetitive active response times of the unit, representations of a required predetermined sequence of the magnitudes of instantaneous measurements determined by the associated sources. The display is repeated in each of the uniformly repetitive active response times of the unit, with modifications in the display in response to any changes in the magnitudes of the instantaneous measurements occurring between the consecutive response times. Hence, comparisons between the different magnitudes of instantaneous measurements displayed in each response time, and possibly also comparison between the different magnitudes of instantaneous measurements displayed in consecutive response times, readily can be made.

The relevant data signals from the different associated data sources, and causing any required predetermined sequence of the corresponding output signals, are multiplexed within the data display apparatus, the corresponding predetermined sequence of output signals from the common output of the data display apparatus being de-multiplexed by the associated display unit.

If the data display apparatus is included within a system in which are to be made the required measurements by the associated data sources, only a single communication channel between the system and the associated display unit is required. Possibly, the data display apparatus is an integral part of the system, and/or the associated data sources are integral parts of the system. Alternatively, the data display apparatus and/or the associated data sources readily can be removed from the system when no longer required.

The term magnitudes of instantaneous mea surements is employed in this specification, and the accompanying claims, to refer to measurements each detected individually in as short a time as possible so that the magnitude of the measurement does not change whilst it is being so detected.

It is not essential that the parameter of each relevant data signal from the associated sources, the magnitude of which parameter represents the magnitude of an instantaneous measurement determined by the source providing the relevant data signal, is the same as the parameter of each corresponding output signal from the data display apparatus.

It is possible that only one measurement is determined, and displayed, in each of the uniformly repetitive response times, but this is not considered to cause a predetermined sequence of output signals from the common output of the data display apparatus.

Each relevant data signal, causing a corresponding output signal to drive the associated display unit, may comprise an appropriate part a continuous flow of information signals from the corresponding data source, or may comprise a discrete information signal from the corresponding data source, in any event, relevant data signals being provided only intermittently from each data source.

The associated display unit may comprise an oscilloscope, of a conventional construction, and to be controlled by timing means comprising a time base circuit, the uniformly repetitive active response time of the oscilloscope comprising the refresh time of the display provided on the screen of the oscilloscope, the arrangement of the data display apparatus being such that the potentials of the different output signals from the data display apparatus, and supplied to the oscilloscope, represent the magnitudes of the instantaneous measurements represented by the corresponding relevant data signals supplied to the data display apparatus.In each of the consecutive uniformly repetitive active response times of the display there is displayed simultaneously representations of a plurality of different magnitudes of instantaneous measurements of a required predetermined sequence of such measurements. Within each consecutive refresh time of the display, the display has a plurality of constituent parts, each such constituent part representing individually the magnitude of an instantaneous measurement determined by an associated source. Hence, in operation, the display reproduced on the screen of the associated oscilloscope in each refresh time is in the form of a bar-graph, having a plurality of different constituent parts corresponding to the magnitudes of the instantaneous measurements from the different associated data sources.

In order that a flicker-free display is obtained, it is essential to arrange that the instantaneous magnitudes of the measurements detected by the data sources do not change significantly more often that convbni- ently can be observed from the screen of the oscilloscope.

Because the refresh time of the required display on the screen of the oscilloscope usually is short, conveniently, there can be detected, and indicated, in a suitable manner, dynamic conditions in a system in which are made the measurements causing the display, for example, at the switch ON, or at the switch OFF, of the system, or upon unit rnode selection within the system.

Other forms of associated display unit cån be employed, and it is not necessary that the representations of the plurality of different magnitudes of instantaneous measuremerits are displayed simultaneously in each of the consecutive uniformly repetitive active response times in which such representations are required to be displayed. Thus, each such representation may be displayed consecutively and individually in the corresponding constituent sampling time of each of the uniformly repetitive active response times.

The required predetermined sequence of the magnitudes of instantaneous measurements, displayed in each of the consecutive uniformly repetitive active response times of the associated display unit, is determined by the sequencing means of the apparatus according to the present invention.

For any required predetermined sequence of magnitudes of instantaneous measurements required to be displayed, each of the uniformly repetitive active response times of the associated display unit is to be at least equal to the sum of the required sampling times for the representations of the different magnitudes to be displayed in the active response time. It is convenient to consider, in this specification and the accompanying claims, that each representation of a magnitude of an instantaneous measurement is provided irl a sampling time, and that each predetermined sequence of output signals from the data display apparatus occurs within a uniformly repetitive active response time of the associated display unit. However, it is not essential that the detected measurements are displayed by the associated display unit substantielly instantaneously with the determination of the measurements.

Any required predetermined sequence, of a plurality of different possible sequences, of output signals, to drive the associated display unit, may be obtained by altering at will the sequence of pulses from the sequencing means; or by altering the ways in which the sequencing means is connected to the switching means, and/or by altering the ways in which the switching means is connected to the associated data sources. For any particular sequence, not all the provided data sources may be required to be connected to the data display apparatus. Thus, in any one of these ways, the connection of provided associated data sources to the data display apparatus according to the present invention is controlled, and the selection of the provided data sources to be connected to the data display apparatus is possible.In any event, the predetermined sequence of the output signals to drive the associated display unit is so determined.

Usually the duration of each sampling time in any required predetermined sequence of output signals is a constant.

It is not essential that the consecutive sampling times of any required predetermined sequence of output signals are co-extensive.

The sequencing means may have any convenient construction. In one form the sequencing means comprises a decoder to be driven by an oscillator with a suitable pulse output repetition frequency, the decoder having a plurality of outputs individually connected to the switches of the switching means, with each switch connected to a decoder output, pulses from the decoder controlling the actuation of the switches in the required manner.

The switches may have any convenient form, for example, comprising field-effect transistors.

It is possible, but not essential, that at least some of the associated data sources, comprising detectors and electrical supply means to energise the detectors, are capable of providing desired common, but not necessarily coextensive, datum lines for the corresponding constituent parts of the provided display, in each of the uniformly repetitive active response times. For convenience in this specification, and the accompanying claims, such data sources will be referred to as matched data sources.Each desired datum line, of each such constituent part of the provided display, represents a predetermined magnitude of the measurements capable of being determined by the corresponding, associated data sources, the predetermined magnitude being considered to be an arbitary zero value of the measurements, and individually desired for the measurements to be made by the corresponding, associated data source.

The common output for the data sources may be coupled to the associated display unit via a differential amplifier of the data display apparatus, the common qutput for the data sources being connected to one input of the differential amplifier, and a predetermined potential is to be applied to the other input of the differential amplifier.

A resistive feedback connection may be provided for the other input of the differential amplifier, the feedback connection comprising part of gain setting means provided within the data display apparatus for the associated display unit. The gain setting means may be adjustable manually when the resistive feedback connection for the differential amplifier includes a potentiometer.

In addition, or alternatively, display offset means may be provided within the data display apparatus, and is coupled to the other input of the differential amplifier. The display offset means may be adjustable manually, by including a variable potential divider connected to a reference potential source. Conveniently, when gain setting means for the associated display unit is provided within the data display apparatus, the display offset means may be coupled to the other input of the differential amplifier via the gain setting means.

Different display offset means may be provided within the data display apparatus for at least some of the different associated data sources, a display offset means being provided individually for each associated data source, the arrangement being such that, when a particular data source of said at least some data sources is causing the supply of an output signal from the common output for the data sources, the corresponding display offset means is coupled to the other input of the differential amplifier, both in response to the same pulse from the sequencing means, the switching means also being connected to the different display offset means in the appropriate manner.Usually the arrangement is such that common datum lines are capable of being provided for each constituent part of the provided display when unmatched data sources are provided within said at least some of the data sources.

According to other aspects the present invention comprises the combination of data display apparatus of any one of the forms referred to above; with a display unit; and/or with a plurality of data sources comprising measuring means.

It is not essential that the plurality of associated data sources each determine the magnitudes of the same type of measurement, the data sources being responsive to different parameters.

At least some of the plurality of associated data sources may determined the temperatures of their ambients. Such data sources may comprise semiconductor devices in the form of diodes, or transistors connected as diodes. Each such semiconductor device may be energised by a constant current source also included in the data source, he potential across the P-N junction of the device being proportional to the ambient temperature, and this potential being detected. Hence, the relevant data signals provided by such data sources are supplied to the common output of the data sources provided within the data display apparatus, and comprise the output signals from the common output of the data sources. Such temperature detecting devices are stable in operation, are easily energised within a system including other semiconductor devices, and are compact.

Common electrical supply means may be provided to energise detectors of at least some of the plurality of data sources.

In addition, or alternatively, different electrical supply means may be provided to energise detectors of at least some of the plurality of data sources.

In any such arrangement, electrical supply means may be connected to the detectors of at least some of the plurality of data sources via switches of the switching means, the arrangement being such that, in response to each appropriate pulse from the sequencing means, the electrical supply means only energises the selected detector of said at least some data sources, to provide the corresponding required relevant data signal.

In addition, or alternatively, at least some of the switches of the switching means may be connected to the outputs of the detectors of at least some of the data sources, the arrangement being such that, in response to each appropriate pulse from the sequencing means, the selected switch passes the corresponding required relevant data signal supplied by the detector connected to the selected switch.

The present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is of a bar-graph display on the screen of an associated oscilloscope driven by one embodiment of data display apparatus according to the present invention, in response to the magnitudes of instantaneous measurements determined by ten different measuring means comprising data sources, the data sources being associated with the data display apparatus, representations of the ten magnitudes being displayed simultane ousty, and Figure 2 is a circuit diagram of one embodiment of data display appratus according to the present invention, together with ten associated data sources.

The data display appratus shown in Fig. 2, comprises means to drive an associated display unit, the associated display unit comprising an oscilloscope 10 of a conventional construction, and the data display apparatus operating in response to relevant data signals from ten associated data sources, comprising measuring means, and indicated generally at 11.

It is required that the data display apparatus drives the oscilloscope 10 to cause a display of the bar-graph form shown in Fig. 1, and comprising the simultaneous representations of ten magnitudes of instantaneous measurements determined by the data sources 11.

The ten data sources 11 are indicated as comprising both ten temperature detectors in the form of diodes D1 ... D1O, and electrical supply means to energise the detectors, and the sources are referred to in detail below.

The data sources, and the data display apparatus, are located within a system, and the temperatues of the adjacent parts of the system to the detectors D1 . . D10 are required to be displayed in the bar-graph form of Fig.

1, so that the different simultaneous temperatures of the different parts of the system easily can be compared, and the inter-relationship of changes of these temperatures within the system readily can be examined.

The data display apparatus includes sequencing means comprising both an oscillator circuit, indicated generally at 20, and providing pulses at a repetition frequency of 1 Kilohertz, and a 1 of 10 decoder indicated generally at 21, and of a conventional construction. The output of the oscillator circuit 20 is provided to the 1 of 10 decoder 21, to drive the decoder, so that a pulse is provided in turn on each of the ten outputs 22 of the decoder, such a pulse being provided in response to each pulse from the oscillator 20.

The output of each detector D1 ... do 0 individually is connected to a switch comprising a field-effect transistor, different detectors being connected to different switches S1 . .S10. The switches comprise switching means of the data display apparatus. The switches S1 . .S10 individually are controlled by the gates of the field-effect transistors being connected individually to the outputs of the decoder 21, each switch being closed in response to a pulse from the corresponding output 22 of the decoder. In response to each pulse from the decoder 21 a relevant, corresponding data signal is to be supplied from the switch so selected.Each relevant data signal comprises part of a continuous flow of information signals from the corresponding data source, relevant data signals being provided only intermittently from each switch, and hence being considered as being provided only intermittently from each data source.

The outputs of the switches S1 . .StO are commoned at a point P, comprising a common output for the data sources provided within the data display apparatus.

Each relevant data signal passed by the switches, is passed indirectly in a manner referred to below, from the common output P, to the oscilloscope, in the appropriate manner, the potential of each output signal from the data display apparatus being representative of the magnitude of the instantaneous measurement determined by the corresponding data source.

In the operation of the data display apparatus, each switch S1 ... 510 is closed in turn, in response to pulses from the decoder 21, only one switch being closed at any particular time. Thus, there is obtained, in response to each sequence of pulses from the decoder, a corresponding sequence of rele vant data signals from the point P.

The output signals from the data display apparatus, to drive the oscilloscope 10, are supplied to the oscilloscope over a single communication channel 24. Hence, the relevant data signals from the different associated data sources are multiplexed within the data display apparatus, the corresponding predetermined sequence of output signals from the data display apparatus being de-multiplexed by the oscilloscope.

The sequencing means operates in a uniformly repetitive manner, and a sequence of output signals to drive the oscilloscope is provided in a uniformly repetitive manner. If in successive sequences of output signals the same output signals are provided, these cause the corresponding constituent parts of the provided bar-graph display to be refreshed in response to each such output signal. However, if corresponding output signals in the successive sequences have different potentials, due to changes in the magnitudes of the instantaneous measurements detected by the corresponding data sources, the corresponding constituent parts of the provided bargraph display will change in accordance with the changes in potential of the corresponding signals.In order that a flicker-free display is obtained, it is essential to arrange that the magnitudes of the instantaneous measurements detected by the data sources do not change significantly more often than conveniently can be observed from the screen of the oscilloscope.

The bar-graph display has a refresh time of 10 milliseconds, the persistence time of the phosphor on the screen of the oscilloscope being required to be longer than this refresh time.

Each output signal from the data display apparatus is provided for a sampling time, each such sampling time being less than 1 millisecond, it being required that the sum of the different sampling times of the different output signals, for each predetermined sequence of output signals, is less than the refresh time of the display. Each switch S1 . .S10 is closed selectively for the sampling time.

The operation of the decoder 21 is controlled by the time base circuit of the oscilloscope, which, for convenience, is indicated generally at 30. The output of the time base circuit 30 is connected to the decoder 21, the arrangement being such that the manner of operation of the decoder, and each sequence of output signals from the data display apparatus, is synchronised with the manner of operation of the time base generator 30. In particular, the time base circuit is such that the oscilloscope has a uniformly repetitive active response time, or refresh time of the display on the screen of the oscilloscope.

The sampling times in which output signals from the data display apparatus are supplied to the oscilloscope occur consecutively, and individually, in the refresh times of the display on the oscilloscope screen. Output signals in corresponding sampling times in each of the consecutive uniformly repetitive active response times are in response to relevant data signals from the same source.

Thus, there is repeatedly displayed on the oscilloscope screen, in each of the consecutive refresh times of the oscilloscope, representations of the sequence of the magnitudes of instantaneous measurements determined by the associated sources. Modifications in the display occur in response to any changes in the magnitudes of instantaneous measurements occurring between the consecutive refresh times.

The cathodes of the diode detectors D1 . . . D10 are connected to a rail 40 maintained at zero potential and the anodes are connected individually via a resistor, respectively, R1 . . R10, to a rail 41 maintained at a reference potential + V3. A point between each such series combination of a diode and a resistor is connected to a switch S1 . . .S10.

A constant current is supplied to each of the diodes D1 . . D10, and the potential across each diode is indicative of the temperature of the P-N junction.

The diodes D1 . . . D10 may be replaced by transistors connected as diodes.

Detectors comprising semiconductor devices, such as diodes or transistors, are advantageous in that they are stable in operation, are easily energised within a system including other semiconductor devices, and are compact.

The common output P for the switching means is connected to the non-inverting input of a differential amplifier Al. The inverting input of the differential amplifier Al is connected to the output of the amplifier via a resistive feedback connection including a resistor R11, and also includes a variable resistor R12, one end of which is connected to the output of an operational amplifier A2. The operational amplifier A2 has a resistive feedback connection R 1 3 connected to its inverting input, which input is also connected via a resistor R14 to the tapping point of a variable resistor R1 5. A reference potenfial of - V3 is supplied to one end of the variable resistor R 1 5, and the other end is connected to a point maintained at zero potential.The noninverting input of the operntional amplifier A2 is connected to a point maintained at zero potential. The output of the differential amplifier Al is connected to the oscilloscope 10, to drive the oscilloscope.

Within the differential amplifier Al each relevant data signal is compared with the output of oscilloscope off-set means, comprising the arrangement connected to the end of the variable resistor R 1 2 remote from the differential amplifier Al. The output of the differential amplifier is proportional to any difference between the magnitudes of the source output signal, as supplied to the noninverting input to the differential amplifier, and the signal supplied to the inverting input to the differential amplifier, if the former is greater than the latter.If any such difference in magnitudes is detected by the differential amplifier, a corresponding part is obtained in the bar-graph display on the oscilloscope screen, the value of the difference corresponding to the height of the bar-graph part above the base line of the bar-graph, determined by the off-set means referred to above. The height of the bar-graph part, for a particular detected temperature, is determined by gain setting means, comprising the resistive feedback connecting R11 and the variable resistor R12, the gain being R11 1 + .

R12 The output Q of the differential amplifier Al comprises the common output for the output signals from the data display apparatus to drive the oscilloscope in the appropriate manner.

It is desired that the different constituent parts of the display have common, co-extensive, datum lines when the system to be monitored is not operating, but the data display apparatus and the temperature detectors are switched ON. With the diodes D1 . . . D10 initially matched it is only required that the resistors R1 ... rio are identical.

If the diodes D1 . . . D10 are not initially matched, the desired initial response, referred to above, can be obtained by adjusting the resistors R1 . . . R10 in the appropriate manner. However, variations in the outputs of the constant current sources, including the resistors R 1 ... R 10, cause corresponding variations in the manners of response of the corresponding diodes D1 . . . D10 to changes in temperature, which is undesirable.

A common constant current source for at least some of the different diodes D1 ... do 0 may be provided, and the switching means S1 ... 510 may be connected between the common constant current source and the diodes, instead of being connected to the outputs of the diodes. Thus, the detectors provide only discrete, intermittent, information signals, each comprising a relevant data sig nai, when energised selectively in response to pulses from the sequencing means. If the diodes are matched, the desired common, coextensive datum lines are obtained for the oscilloscope display.

Even if unmatched diodes are provided, it is possible to provide a common constant current source for the diodes, and the desired common, coextensive datum lines are obtained for the display, if different oscilloscope display off-set means are provided for the different diodes, with an oscilloscope display off-set means provided for each diode individually. The different oscilloscope display off-set means are connected to the switching means S1 . . . 510, and the arrangement is such that the corresponding oscilloscope display off-set means is connected selectively to said other input of the differential amplifier Al when an output signal, caused by a diode, is supplied to said one input of the differential amplifier, both in response to a pulse from the sequencing means.In this way any differences in the initial responses of the different diodes can be compensated, by providing the appropriate different oscilloscope display offset means, and the required common, coextensive datum lines for the display are obtained.

Because the refresh time of the required display usually is short, conveniently, there can be detected, and indicated, in a suitable manner, dynamic conditions in a system in which are made the measurements causing the display, for example, at the switch ON, or at the switch OFF, of the system, or upon unit mode selection within the system.

It is not essential that the detected measurements are displayed substantially instantaneously on the screen of the oscilloscope with the determination of the measurements.

The illustrated data display apparatus may be calibrated, say, at 20"C and 100'C, so that absolute values of the detected temperatures can be obtained by taking appropriate readings from the oscilloscope display.

The associated display unit may be other than an oscilloscope, and may have any convenient form, but is required to have timing means to control its manner of operation, so that the display unit has a uniformly repetitive active response time determined by the timing means. Thus, a parameter of each output signal from the data display apparatus other than its potential may represent the magnitude of the instantaneous measurement represented by the corresponding relevant data signal. A display other than a bar-graph dis play may be obtained. Further, it is not essential that representations of each output signal, of each sequence of output signals, from the data display apparatus are displayed simulta neously in a uniformly repetitive active response time of the display unit, but each such representation could be displayed consecutively and individually.

Various other modifications are possible to the data display apparatus according to the present invention.

The switching means may have any conve nient form.

The gain setting means and/or the display off-set means may be omitted, or have forms other than those illustrated.

The arrangement may be such that a plurality of different output signals are capable of being supplied in any required predetermined sequence, synchronised with time base signals of the associated oscilloscope, from the point Q in each of the consecutive, uniformly repetitive active response times of the display unit.

Any required predetermined sequence, of a plurality of different possible sequences, of output signals, to drive the associated display unit, may be obtained by altering at will the sequence of pulses from the sequencing means; or by altering the ways in which the sequencing means is connected to the switching means, and/or by altering the ways in which the switching means is connected to the associated data sources. For any particular sequence, not all the provided data sources may be required to be employed. Thus, in any one of these ways, the connection of provided data sources to the data display apparatus is controlled, and the selection of the provided data sources to be connected to the data display apparatus is possible. In any event, the predetermined sequence of the output signals to drive the associated display unit is so determined.

The sequencing means may have any convenient form, and may be flexible in operation so that a selected one of a plurality of different possible sequences of pulses may be provided therefrom. For any particular sequence, not all the provided switching means may be required to be employed.

Usually the duration of each sampling time for any required predetermined sequence of output signals is a constant.

At least some of the data sources may not include temperature detectors, but instead include detectors responsive to parameters other than temperature. Such data sources, whilst including electrical supply means to energise the detectors, may not include constant current sources.

The data display apparatus may not be an integral portion of a system, measurements of parameters within constituent parts of which system are required to be displayed. Further, the associated data sources, comprising measuring means, may not be integral portions of such a system.

Claims

1. Data display apparatus to drive in an appropriate manner an associated display unit, the associated display unit having timing means to control the manner of operation of the display unit so that the display unit has a uniformly repetitive active response time determined by the timing means, the operation of the data display apparatus partially being in response to data signals supplied thereto by a plurality of associated sources, each associated source comprising measuring means, and including a detector to be energised by electrical supply means, the magnitude of a parameter of each data signal representing the magnitude of an instantaneous measurement determined by the source providing the data signal, the data display apparatus including switching means, having a plurality of switches, arranged such that each data source is to be connected individually to a switch, and different data sources are to be connected to different switches, the switches to be actuated in response to pulses from sequencing means of the data display apparatus, the sequencing means to be connected to the timing means of the associated display unit to receive signals therefrom, so that the manner of operation of the sequencing means is synchronised with the manner of operation of the timing means, and a common output for the data display apparatus is provided between the switching means and the associated display unit, in response both to pulses from the sequencing means to the switching means, and to each of a plurality of relevant data signals received by the apparatus, the apparatus is to provide, from the common output thereof, a plurality of output signals to drive the associated display unit in the appropriate manner, each output signal being provided individually in response to a relevant data signal, and at least corresponding to the relevant data signal, the magnitude of a parameter of each output signal representing the magnitude of the instantaneous measurement represented by the corresponding relevant data signal, the arrangement being such that each output signal is to be provided individually by the data display apparatus to the associated display unit in a sampling time within a uniformly repetitive active response time of the associated display unit, with different such output signals, in response to different relevant data signals, from different ones of the plurality of associated data sources, being provided, in a predetermined sequence, in different sampling times, in each of the uniformly repetitive active response times, output signals in corresponding sampling times in each of the consecutive uniformly repetitive active response times being in response to relevant data signals from the same source, the predetermined sequence of output signals from the apparatus, within each of the consecutive uniformly repetitive active response times, being determined by the sequencing means, and being synchronised with the signals from the timing means of the associated display unit to the switching means.

2. Data display apparatus as claimed in claim 1 and to be employed with an associ ated display unit comprising an oscilloscope to be controlled by timing means comprising a time base circuit, the uniformly repetitive active response time of the oscilloscope comprising the refresh time of the display provided on the screen of the oscilloscope, the arrangement of the data display apparatus being such that the potentials of the different output signals from the data display apparatus, and supplied to the oscilloscope, represent the magnitudes of the instantaneous measurements represented by the corresponding relevant data signals supplied to the data display apparatus.

3. Data display apparatus as claimed in claim 1 or claim 2 in which the sequencing means comprises a decoder to be driven by an oscillator with a suitable pulse output repetition frequency, the decoder having a plurality of outputs individually connected to the switches of the switching means, with each switch connected to a decoder output, pulses from the decoder controlling the actuation of the switches in the required manner.

4. Data display apparatus as claimed in claim 1 or claim 2 or claim 3 in which the common output for the data sources is to be coupled to the associated display unit via a differential amplifier of the data display apparatus, the common output for the data sources being connected to one input of the differential amplifier, and a predetermined potential is to be applied to the other input of the differential amplifier.

5. Data display apparatus as claimed in claim 4 in which a resistive feedback connection is provided for the other input of the differential amplifier, the feedback connection comprising part of gain setting means provided within the data display apparatus for the associated display unit.

6. Data display apparatus as claimed in claim 4 or claim 5 in which display off-set means is provided, and is coupled to the other input of the differential amplifier.

7. Data display apparatus as claimed in claim 6 in which the display off-set means is adjustable manually, by including a variable potential divider connected to a reference potential source.

8. A combination as claimed in any one of the preceding claims in which a single communication channel is provided to extend between the common output for the plurality of data sources and the display unit.

8. Data display apparatus as claimed in claim 6 or claim 7, when dependent on claim 5, in which the display off-set means is coupled to the other input of the differential amplifier via the gain setting means.

9. Data display apparatus as claimed in any one of claims 6 to 8 in which different display off-set means is provided for at least some of the different associated data sources, a display off-set means being provided individually for each associated data source, the arrangement being such that, when a particular data source of said at least some data sources is causing the supply of an output signal from the common output for the data sources, the corresponding display off-set means is coupled to the other input of the differential amplifier, both in response to the same pulse from the sequencing means, the switching means also being connected to the different display off-set means in the appropriate manner.

10. Data display apparatus as claimed in any one of the preceding claims in which a single communication channel is provided to extend between the common output for the associated plurality of data sources and the associated display unit.

11. A combination of data display apparatus as claimed in any one of the preceding claims with a display unit.

12. A combination of either data display apparatus as claimed in any one of claims 1 to 10, or the combination as claimed in claim 11, with a plurality of data sources comprising measuring means.

1 3. A combination as claimed in claim 1 2 in which at least some of the data sources are matched data sources.

14. A combination as claimed in claim 12 or claim 1 3 in which at least some of the plurality of associated data sources determine the temperatures of their ambients.

15. A combination as claimed in claim 14 in which such data sources each includes a semiconductor device in the form of a diode, or a transistor connected as a diode.

16. A combination as claimed in claim 1 5 in which each such semiconductor device is to be energised by a constant current source also included in the data source, the potential across the P-N junction of the device being proportional to the ambient temperature, and this potential being detected.

1 7. A combination as claimed in any one of claims 12 to 1 6 in which common electrical supply means is provided to energise detectors of at least some of the plurality of data sources.

1 8. A combination as claimed in any one of claims 1 2 to 1 7 in which different electrical supply means is provided to energise detectors of at least some of the plurality of data sources.

1

9. A combination as claimed in any one of claims 12 to 1 8 in which electrical supply means is connected to the detectors of at least some of the plurality of data sources via switches of the switching means, the arrangement being such that, in response to each appropriate pulse from the sequencing means, the electrical supply means only energises the selected detector of said at least some data sources, to provide the corresponding required relevant data signal.

20. A combination as claimed in any one of claims 1 2 to 1 9 in which at least some of the switches of the switching means is connected to the outputs of the detectors of at least some of the data sources, the arrange ment being such that, in response to each appropriate pulse from the sequencing means, the selected switch passes the corresponding required relevant data signal supplied by the detector connected to the selected switch.

21. Data display apparatus substantially as described herein with reference to the accompanying drawings.

22. A combination of data display apparatus with an oscilloscope, and/or with a plurality of data sources comprising measuring means.

CLAIMS (23 Jan 1980)

1. A combination of a display unit, data display apparatus to drive in an appropriate manner the display unit, and a plurality of sources of data signals to be supplied to the apparatus, the display unit having timing means to control the manner of operation of the display unit so that the display unit has a uniformly repetitive active response time determined by the timing means, the operation of the data display apparatus partially being in response to data signals supplied thereto by the plurality of sources, the sources comprising matched temperature responsive diodes, the magnitude of the potential of each data signal representing the magnitude of an instantaneous temperature determined by the source providing the data signal for its ambient, and common electrical supply means is provided to energise the diodes, each diode to be energised by a constant current source, included in the data source, the potential across the P-N junction of the diode being proportional to the ambient temperature, and this potential being detected, the data display apparatus including switching means, having a plurality of electronic switches, arranged such that each diode output is connected individually to a switch, and different diode outputs are connected to different switches, the switches to be actuated individually in response to pulses from sequencing means of the data display apparatus, so that the selected switch passes the corresponding required relevant data signal from the data source connected thereto, the sequencing means being connected to the timing means of the display unit to receive signals therefrom, so that the manner of operation of the sequencing means is synchronised with the manner of operation of the timing means, and a common output for the data display apparatus is provided between the switching means and the display unit, in response both to pulses from the sequencing means to the switching means, and to each of a plurality of relevant data signals received by the apparatus, the apparatus is to provide, from the common output thereof, a plurality of output signals to drive the display unit in the appropriate manner, each output signal being provided individually in response to a relevant data signal, and at least corresponding to the relevant data signal, each output signal is to be provided individually by the data display apparatus to the display unit in a sampling time within a uniformly repetitive active response time of the display unit, with different such output signals, in response to different relevant data signals, from different ones of the plurality of data sources, being provided, in a predetermined sequence, in different sampling times, in each of the uniformly repetitive active response times, output signals in corresponding sampling times in each of the consecutive uniformly repetitive active response times being in response to relevant data signals from the same source, the predetermined sequence of output signals from the apparatus, within each of the consecutive uniformly repetitive active response times, being determined by the sequencing means, and being synchronised with the signals from the timing means of the display unit to the switching means.

2. A combination as claimed in claim 1 in which the display unit comprises an oscilloscope to be controlled by timing means comprising a time base circuit, the uniformly repetitive active response time of the oscilloscope comprising the refresh time of the display provided on the screen of the oscilloscope.

3. A combination as claimed in claim 1 or claim 2 in which the sequencing means comprises a decoder to be driven by an oscillator with a suitable pulse output repetition frequency, the decoder having a plurality of outputs individually connected to the switches of the switching means, with each switch connected to a decoder output, pulses from the decoder controlling the actuation of the switches in the required manner.

4. A combination as claimed in claim 1 or claim 2 or claim 3 in which the common output for the data sources is coupled to the display unit via a differential amplifier of the data display apparatus, the common output for the data sources being connected to one input of the differential amplifier, and a predetermined potential is to be applied to the other input of the differential amplifier.

5. A combination as claimed in claim 4 in which a resistive feedback connection is provided for the other input of the differential amplifier, the feedback connection comprising part of gain setting means provided within the data display apparatus for the display unit.

6. A combination as claimed in claim 4 or claim 5 in which display off-set is provided, and is coupled to the other input of the differential amplifier.

7. A combination as claimed in claim 6 in which the display off-set means is adjustable manually, by including a variable potential divider connected to a reference potential source.