GB1431724A - System for acquiring processing and displaying information - Google Patents

Abstract

1431724 Cathode-ray tube displays TEKTRONIX Inc 18 Dec 1973 [8 Jan 1973] 58502/73 Heading H4T The invention is concerned with an oscilloscope in which input waveform information comprising X and Y analogue quantities together with Z axis information and alpha-numeric data may be displayed in real-time or may be digitized, stored in a memory and after any required processing, e.g. by a computer, reconverted to analogue form and displayed. The display device of the oscilloscope may comprise a cathode-ray tube or a pen recorder. Fig. 2, shows the general arrangement in which real-time vertical and horizontal information inputs 14, 16 are supplied to switches 32, 34 and to respective sample and hold circuits 18, 20 supplying respective A/D converters 22, 24 the outputs of which comprising data (Y- axis) and address information (X-axis) are stored in a memory 25. The stored information is then processed by a digital computer 27 and reconverted to analogue form in D/A converters 28, 30 the outputs of which are supplied selectively via switches 32, 34 selectively with the real time information to the display device 35. Fig. 3 shows a detailed block diagram of the system comprising an acquisition unit 50, a processing unit 51, a display unit 52 and an external computer 53, units 50 and 52 forming a conventional oscilloscope when connected together. The acquisition unit 50 includes two vertical channel units 60, 62 (e.g. comprising attenuators and switched gain pre-amplifiers) supplied with information, e.g. via a probe or coaxial cable, and two horizontal channel units 64, 66 supplying a plurality of selectable time base sweep signals and also comprising amplifier channels for signals to be displayed on the horizontal axis, the required outputs being selected by respective channel switches 63, 67. Such selected outputs are supplied to respective sample and hold circuits 75, 74 in processing unit 51 which receive clock pulses from an A/D converter 77 (the clock input to 74 being delayed in delay 78 to compensate for the inherent delay in the start of the time base sweep) and the samples after conversion to digital form in A/D converter 77 are stored in memory 82. The acquisition unit 50 also includes an Z-axis generator and a read-out circuit 69 (providing alpha-numeric data). In operation, under the control of logic circuitry the data in memory 82 is interchanged with and when required, modified by, computer 53 and then routed via a display generator 90 of known type and which includes D/A converters, to the display unit 52 via channel switches 71, 72 through which the real-time information may also be routed to the display. The alphanumeric data from read-out circuit 69 (derived from the computer via read-out interface 83 and input-output interface 85) comprises X, Y and Z-axis data and on command such data is fed directly to the display unit 52.