DE2941005A1 - Storage oscilloscope with digital signal generation facility - has stored oscilloscope display scanned at control rate to generate equivalent digital signal - Google Patents

Abstract

The memory oscilloscope system with a facility for analogue signal display storage is also combined with a facility to generate an equivalent digital version that can be separately stored in memory. When an input pulse (1) triggers a signal generator (2), an analogue signal (3) is produced that is fed to the tube (4) of an oscilloscope. The signal is held for display in a layer of the CCD elements. Independently of the display storage, a separate tube (6) is used to scan the display on a line basis. The generated digital signal (7) may be processed by a computer (8) or held in memory for recall at a later point.

Description

Converter for converting a one-time, fast electrical

Signal into a digital signal In measurement technology, the task often occurs on, an aperiodic, once-occurring fast electrical signal more precisely to investigate. This task exists, for example, when examining a by pressure scan (DE-PS 15 74 489) obtained PCM tone signal with a frequency of 1-2 MHz.

A certain signal may only come from here once the recording medium and should with regard to its quality, its edge steepness and other parameters are examined more closely.

It is known to display such a signal on an oscilloscope and to take pictures. This Fotographiervor gang requires but not inconsiderable Cost and is generally cumbersome to implement. There can also be subtleties get lost in the waveform.

Fast oscilloscopes are also known in which a signal stored analogously in a certain instant of time and then a certain time can be reproduced. These But time is down to a few minutes limited and therefore does not allow a particularly fine and precise analysis of the signal curve.

The invention is based on the object of a converter for converting a one-time, fast electrical signal into a digital one for input into to create a computer suitable signal.

This object is achieved by the invention described in claim l solved. Advantageous further developments of the invention are described in the subclaims.

In the invention, therefore, the fast signal is generated with, for example, an electron beam Written without inertia in the analog memory, where it is available for a relatively long time is. The read process can then be carried out independently of the write process with the desired Speed and deliver a digital signal that goes straight to a computer can be entered and stored there digitally.

The analog storage of the signal in the layer can be different Be carried out in a manner, e.g. by storing load carriers, by changing capacities, by changing magnetic properties or the ohmic resistance of the layer at the individual places.

The digital signal obtained and stored in a computer can then as often as required to reproduce the original one-time fast signal can be used, e.g.

by writing in a plotter, by displaying it on an oscilloscope or similar. Since now the time for studying the fast signal is arbitrary is long, a proper investigation of the signal is possible.

The invention is based on the drawing of an exemplary embodiment explained. Show in it Figure 1 is a schematic diagram of the invention and FIG. 2 shows a diagram to explain the mode of operation.

In FIG. 1, the signal transmitter delivers 1 on the basis of a trigger pulse 2 once a short electrical signal 3 with any frequency. This Signal reaches the cathodes.

jet tube 4 and is driven with this tube at the speed V1 read into layer 5, which stores analog data. The signal is then in the shift 5 included for a longer period of time, depending on the type of storage is.

In the case of a charge carrier storage layer in the form of a so-called CCD or CTD. switching, this time can be several hours or days. The parts 2-5 thus form an oscillograph, so to speak, which the signal spatially through linear Inscribes the time deflection of a ray into a layer.

Regardless of the writing process, the cathode ray tube is used 6 the layer 5 is scanned line by line, i.e. the signal stored in the layer 5 queried. This scanning takes place at a lower speed V2. By this scanning produces the digital signal 7 which is fed to the computer 8. The digital signal 7 is stored there for any length of time. At the Terminal 9 therefore has a digital signal available for any length of time with which the original Signal 3 shown, written or otherwise evaluated for an analysis can be.

Figure 2 shows the storage layer 5. This is in this layer Signal 3 is stored by an electron beam directed in the direction of the Time axis s linear in time and perpendicular to it according to the amplitude of the signal eye.

is steering. The signal 3 is then spatially similar to that on an oscilloscope screen stored in layer 5.

During the reading process, the reading beam starts at the first point 11. Simultaneously a counter is started. The scanning occurs line by line vertically to the direction s with constant deflection speed. The reading beam hits at point 12 to the point where signal 3 is stored. The reading beam is now modulated and supplies a signal that stops the counter started in point 11. Its output size is therefore a measure of the respective amplitude, i.e. the Y value of the signal 3 im Time of the first point 11. At the end 13 of this trailing edge, the scanning is running the scanning beam along the dashed line with increased deflection speed back to the next point ll, from where a new scan up to the next point 12 begins. In this way, the stored signal 3 becomes equidistant Points in time and thus also at equidistant points on the X-in axis, i.e. the figure 2 with s labeled time axis, scanned. The values obtained in each case are stored in the form of digital signals. You can then play the in figure The signal 3 shown in FIG. 2 can be used as often as desired.

The writing and reading process can actually be done with the same unit, e.g. the same cathode ray tube. This is then initially for the Writing process used with a deflection speed V1 and then on the Reading process switched. Reading speed is then generally lower than the writing speed. All parts shown preferably form a structural one Unit.

Claims (10)

Claims 1. Converter to implement a one-time, fast electrical signal into a digital signal suitable for input into a computer, characterized in that the signal (3) is spatially in a storing layer (5) and this layer is then written in line by line with a reading beam is scanned. 2. Converter according to claim 1, characterized in that the writing process takes place with an electron beam. 3. Converter according to claim 1, characterized in that the reading process done with a vidicon. 4. Converter according to claim 1, characterized in that the row direction during the reading process is perpendicular to the spatial writing direction (5). 5. Converter according to claim 1, characterized in that the reading process takes place so slowly that the signals obtained are entered into a digital memory (8) can be. 6. Converter according to claim 1, characterized in that during the reading process a counter is started at the beginning (ii) of a line scan, the status of which is at the moment (12) when the read beam hits a memory location of the signal hits, serves as a digital signal (7). 7. Converter according to claim 1, characterized in that for the writing process and the reading operation uses the same scanning unit such as a cathode ray tube will. 8. Converter according to claim 7, characterized in that the scanning speeds during the write process and during the Reading process are different. 9. Converter according to claim i, characterized in that the writing device (4), the storage layer (5) and the reading device (6) combined into one structural unit are. 10. Converter according to claim 1, characterized in that the layer (5) is a charge carrier storing layer.