... | ... | @@ -64,16 +64,113 @@ the illustrated signal. This can even lead to that the input signal |
|
|
is indicated in steps. This effect can be contracted when the
|
|
|
memory depth is increased.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
== Vertical Scaling
|
|
|
|
|
|
The calculation of the vertical scaling is closely linked to
|
|
|
the analog front-end. In Equation 3, the parameter adcin is
|
|
|
an 8-bit value. This value needs to be converted to a voltage
|
|
|
level value (vreal) to update the measurement fields in the
|
|
|
level value (Vreal) to update the measurement fields in the
|
|
|
GUI. The parameter adc0 is the virtual zero line of the ADC
|
|
|
and amounts to 133. The constant parameter adcValUp is the
|
|
|
maximum ADC value (195) before the input signal clips. The
|
|
|
parameter ampmax represents the maximum voltage level [Vp]
|
|
|
of the corresponding amplification stage.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
image::https://es.technikum-wien.at/openlab/openlab_wiki/wikis/img/SignalToolkit_Oscilloscope/SignalToolkit_Oscilloscope_Formula3.PNG[caption="Formula 3: ",title="Calculates the voltage level Vreal for updating the measurement fields",align="center"]
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
Equation 4 is utilized to adjust the voltage level Vreal according
|
|
|
to the vertical position and scaling factor of the corresponding knobs. The signal graph of the GUI has 8
|
|
|
divisions on the y-axis.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
image::https://es.technikum-wien.at/openlab/openlab_wiki/wikis/img/SignalToolkit_Oscilloscope/SignalToolkit_Oscilloscope_Formula4.PNG[caption="Formula 4: ",title="Calculates the voltage level Vdisp for drawing the signal correctly on the graph",align="center"]
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
The parameter pos0 is the virtual zero line of the GUI. The
|
|
|
addition of the parameter pos0 makes it possible to modify
|
|
|
the vertical position of the waveform. The parameter voltsdiv
|
|
|
is bound to the vertical scale knob. During the modification of
|
|
|
the vertical scale knob, the displayed waveform would enlarge
|
|
|
or reduce.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
== Sequential Equivalent Time Sampling Data Processing
|
|
|
|
|
|
The GUI has an essential purpose regarding the SETS data
|
|
|
processing. In case the maximum sample rate of the ADC
|
|
|
is exceeded, the development board needs to be informed
|
|
|
with additional instructions to start the SETS mode. These
|
|
|
instructions are calculated in the GUI and contain the required
|
|
|
sample rate, acquisition rounds, and acquisition packet size.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
Equation 5 is necessary to calculate the required sample rate
|
|
|
to process the input signal properly. The parameter SAframe
|
|
|
represents the maximum samples, which are illustrated within
|
|
|
one frame. In this case SAframe amounts to 600 samples.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
image::https://es.technikum-wien.at/openlab/openlab_wiki/wikis/img/SignalToolkit_Oscilloscope/SignalToolkit_Oscilloscope_Formula5.PNG[caption="Formula 5: ",title="Calculates the required sample rate in SETS",align="center"]
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
Equation 6 is utilized to compute the required acquisition rounds.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
image::https://es.technikum-wien.at/openlab/openlab_wiki/wikis/img/SignalToolkit_Oscilloscope/SignalToolkit_Oscilloscope_Formula6.PNG[caption="Formula 6: ",title="Calculates the required acquisition rounds in SETS",align="center"]
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
The acquisition packet size consists of the division of
|
|
|
SAframe and the maximum sample rate SRADJ . Figure 6
|
|
|
illustrates an example of the reconstruction of one SETS
|
|
|
sample packet. In this example the adjusted sample rate
|
|
|
in the GUI was set to 10 MSa/s (delta x). Thus, the required
|
|
|
acquisition rounds amount to 4 rounds, whereas one packet
|
|
|
consists of 150 sample values.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
The GUI stores every single received sample packet temporarily
|
|
|
until all acquired packets are available. The signal
|
|
|
graph in Figure 6 highlights the sample process as a function
|
|
|
of time. Due to the fact that the maximum sample rate is
|
|
|
limited, the input signal needs to be sampled over more than
|
|
|
one acquisition round. In this example, four time periods
|
|
|
are necessary to sample the input signal according to the
|
|
|
SETS technique. In Figure 6, the parameter delta y represents
|
|
|
the maximum ADC sample rate SRreq.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
image::https://es.technikum-wien.at/openlab/openlab_wiki/wikis/img/SignalToolkit_Oscilloscope/SignalToolkit_Oscilloscope_SETS1.PNG[caption="Figure 1: ",title="SETS Sample Packet Acquisition",align="center"]
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
Figure 7 shows the interleaving process of the acquired
|
|
|
sample packets. The GUI interleaves every single packet, if
|
|
|
all required data packets are completely received.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
image::https://es.technikum-wien.at/openlab/openlab_wiki/wikis/img/SignalToolkit_Oscilloscope/SignalToolkit_Oscilloscope_SETS2.PNG[caption="Figure 1: ",title="ETS Packet Interleaving",align="center"]
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
The signal graph of the GUI is only updated when all acquired sample packets are available.
|
|
|
|
|
|
{empty} +
|
|
|
|
|
|
== https://es.technikum-wien.at/openlab/openlab_wiki/wikis/home[Home] | https://es.technikum-wien.at/openlab/openlab_wiki/wikis/project_des[<Project Description] | https://es.technikum-wien.at/openlab/openlab_wiki/wikis/SOTA_osci[State of the Art Research (Oscilloscope)>] |