Problem using the Write to SGL VI and Read from SGL VI

Question

Hello Sir, I have a problem using the Write to SGL VI. When I am trying to write the captured data using DAQ board to a SGL file, I am unable to store the data as desired. There might be some problem with the VI which I am using to write the data to SGL file. I am not able to figure out the minor problem I am facing. I am attaching a zip file which contains five files.
1) Acquire_Current_Binary_Exp.vi -> This is the VI which I used to store my data using Write to SGL file.
2) Retrive_BINARY_Data.vi -> This is the VI which I used to Read from SGL file and plot it
3) Binary_Capture -> This is the captured data using (1) which can be plotted using (2) and what I observed is the plot is different and also the time scare is not as expected.
4) Unexpected_Graph.png is the unexpected graph when I am using Write to SGL and Read from SGL to store and retrieve the data.
5) Expected_Graph.png -> This is the expected data format I supposed to get. I have obtained this plot when I have used write to LVM and read from LVM file to store and retrieve the data.
I tried a lot modifying the sub VI’s but it doesn’t work for me. What I think is I am doing some mistake while I am writing the data to SGL and Reading the data from SGL. Also, I don’t know the reason why my graph is not like (5) rather I am getting something like its in (4). Its totally different. You can also observe the difference between the time scale of (4) and (5).
Have a Good Day
Regards,
Krishna
Attachments:
LABVIEW_Files.zip ‏552 KB

Answer 1

As already discussed a while ago, your binary data does not contain timing information. You need to tell it the scan rate so it can reconstruct the time axis correcty.
From the data, it seems the sample file was recorded at 0.5MHz. Take the inverse and set the time increment. Voila!
Your sample file is two column data with one colum all zero. You need to set the number of columns to two, to only get the good data in channel 1.
Your acquisition program contains unecessary FOR loops, you can remove the inner loops without change in result.
It makes no sense to convert to SGL if you initialize the shift registers with an empty DBL array. You need to initialize with an empty SGL array.
(The code could be simplified quite a bit more, but this should give you some directions).
The attached zip shows some ideas (LabVIEW 7.1).
LabVIEW Champion . Do more with less code and in less time .
Attachments:
LabVIEW_FilesMOD.zip ‏195 KB