how to read a certain range from binary file

[CSUEB]

Dear all LabView experts!

I've attempted to acquire data as fast as I can from TDS 2024 via GPIB interface. The data will be saved into one binary file and be used for later analysis.
The program that is included here will perform continuous acquiring and save all the points into 1 file.
I used WHILE loop to do this job and each loop will take 2500 points from the scope.
After that, I would like to read the file such that every 2500 points will be read out and analyzed.
can you please show me how to do this?
I've acknowleged that 2 inputs: pos. mod and pos.offset should be able to provide random access to the binary at any point. However, I cannot have this done
THank you very much

[tbd]

Hi CSUEB,

      Perhaps this will work for you - or give you some ideas.  I got rid of the stacked-sequence (they're generally discouraged here) and added a loop to provide ability to review multiple plots.  Couldn't run it without the scope, but the changes are pretty straight-forward.  Please reply if it doesn't work or if you have any questions.

[CSUEB]

Thanks millions

I have labview 6 not 7.1. I would try to install labview 7 within 3 days.

One more point: I would to like access binary file, say, reading out first 2500 points, reading out next 2500 points ....

I've read the HELP section and realized that pos. mode and pos.offset could be able to perform this task. Can you please show me how to do that?

Thanks so much

[tbd]

... one more try (in 6i)...

Again, pls let me know if it doesn't work.

[CSUEB]

first of all, thanks million for your neat program

however, the reading-file part failed! I got error #4 from module READ-FILE. I don't understand the "PLOT INDEX".

My idea is that, the program has been able to continuously acquire data from the scope. The missing module (you left a question mark) was replaced by my driver for TDS 2024; it will get 2500 points each runs. The file will contain 2500 x numer_of_iteration points. I would like to read every 2500 points within the file. Does the PLOT INDEX mean the number of set (the set will contain 2500 points).?

thanks alot for you help

PS: here is the driver

[CSUEB]

there is another point. When I set the PLOT INDEX to be 0, the program was able to read the entire file! (on the graph, it showed multiple plots overlapping each others). I'm sorry if I did not explain so well. The idea is that:

1. The bin file contains multiple plots (each plot will be consisting of 2500 points taken from the TDS scope).

2. I'd like o use some sort of WHILE loop to read each plot and feed it into another VI that will analyze the data. In order to do that, I used pos.mode and pos.offset to access the fine at any range I want. For example, first plot will be from 0 to 2500, second will be 2501 to 5000 so on and so forth. But I couldn't use the right values of pos.mode and pos.offset to achieve it.

When I change PLOT INDEX to be 1 (any values that's greater than 0), I got ERROR #4 from the module READ FILE

Can you please check it?

Thanks alot

[CSUEB]

Again, sorry for mistyping.

1. If I set PLOT INDEX = 0, the first iretation return no error. But from the second iteration, it returns error 4

2. If I set PLOT INDEX = 1 (anything greater than 0), the error is 4

[CSUEB]

this is my BIN file

[tbd]

Hi CSUEB,

      Thanks for your patience - and for the sample data.

Here's a Reader VI that will work (as long as the byte-stream type length is 20004 elements.)

Cheers!

[CSUEB]

I have to say thanks million for you help!
By the way, just others concept questions:
1. How did you get the number 20004?
2. YOu set the time to be 333 ms. What does this do? Is it making the iteration be executed every 333 ms?

thank you so much