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Getting Problem in XY Chart while the same plot is plotting rightly by the Chart Recorder (Using USB-202 and DASYLAB 2022)


Syed Sibtul Hassan Sherazi

Question

I have been trying to plot the graph using the X/Y Chart on the X-axis (Analog Output Values 0 to 1 Volts) and the Y-axis (Analog Input coming from the Opm apm which ranges from 2 to 3 Volts), but have been facing the below-mentioned error. I have attached the DSB file herewith. Please suggest me the changes or do the required modifications. 

image.thumb.png.a35d26923f9935431cc3e65ebee6a257.png

 

I plotted the Analog Output and Analog Input Separately while Chart Recording and these were done successfully but have the time-axes are on the x-axis. 

image.thumb.png.33a2529f1e515bc8f602eb95d5864071.png

Thanks, and looking forward to hearing from you.  

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The input channels on the x/y chart must receive data from a single time base.  In other words, the time base on the Read Data and the Analog Input modules are different time base. You can fix it by setting the Read Data to use the Analog Input time base. 

 

 

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As suggested by you regarding timebase, In the read data module, I changed the DASYLab Sampling rate to Analog Input (HW). Is it a thing that I need to change as I am not sure about that? Please suggest me. 

image.png.8daf761f8583b15d0bbe917938789f3b.png

After that, I started to have an error related to the scan rate, and in order to cater this error, I changed the Analog input scan rate from 200 to 100 with the same blocksize.  Now, the output of a graph (y-axis or analog input) is quite slow in fact still still as compared to to x-axis (analog output or read data from 0 to 1 Volts). 

Please resolve my problem. I have attached the .DSB file herewith

image.thumb.png.4a072a0597f8a9feda980f4bbb714062.png

 

By the way, what does this HW mean at the end of the Input.

 

Thanks and looking forward to hearing from you. 

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HW means HardWare. This USB-202 time-based circuit is more accurate than the others derived via software algorithms.

I thought the USB-202 could use the HW time base, but it cannot. This is likely because the analog output is slow - 250 S/s maximum. But you cannot use 250 because DASYLab artificially limits the output rate to 100 S/s. I don't know why it works this way. The solution is to set both the Analog Input and the Read Data modules to use the DASYLab time base. Use Measurement->Time Bases->All Settings and change it to 100 S/s block size 10. Also, change the xy chart Delete after setting so it is bigger than the number of points in your file. Otherwise, it will prematurely delete the trace.

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Hi @JRys,

 

I have replaced the analog input and output with the digital input and output and tried to get the output but there exists the same error in XY Chart. 

I have attached my digital data file and DSB file of code as well. Please tell me the problem or modify the attached file. 

Thanks. 

image.thumb.png.4496c8f79d0e9c05c6d05f97d3d2aa01.png

 

Final Digital Code.DSB TTL.TXT

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I have been using DASYLab and USB-202 and I am trying to do the same thing that I did with the analog input and analog output. 

The details are as follows: 

Firstly, I used the TTL module to generate 0 and 1 changing after one and the other for 1 complete minute. (File Attached TTL. Txt)

Secondly, I used the Write File module to write that data. 

Thirdly, I used the Read File Module to read that data and passed it to CH0 (Digital Output Channel 0).

Fourthly, I used that channel data to apply to my 10k ohm resistor connected with TIA

Then I have a TIA (Transimpendance) circuit (SEE image) and TIA output connected to the Digital Input Channel (Digital I/O 1) to Plot results.

Lastly, I provided power and ground to the TIA circuit by DAQ USB-202 V+ and GND.  I have attached the .DSB (Final Digital Code) file too. 

image.jpg

Final Digital Code.DSB TTL.TXT

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The Digital Input and Output modules don't behave the same as the Analog Input and Output. They process only the first sample in a block of data. The analog modules process the whole block. Instead, use the analog input and output as before but with the new data file. 

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