MeganWhite

I am already buffering the data with the polymorphic vi AI config and AI read. What I need is when it writes into write.vi the data should be like header data header data... in each file that is created. And all the files created should be in the same format continuously. Writing lvm does not help as I need to buffer the continuous data. Thanks a lot guys Megan

Sorry guys couldn't get the attachment last time Megan

Hey Guys, I was curious to know if it is possible to add header information to a continuous acquiring data write.vi every second without loosing data? I am attaching the case structure where it writes data till the file size is reached and then writes the header. How can I make a loop so that when the file size is not reached still the header keeps updating after every 1 second duration? Megan

Hey guys, I am able to write a header into the binary file now but I cannot read it in order to write it into a text file. I am using the vi Read File. What byte stream type sould I specify if the data file contains ascii header and binary data? I am attaching a snapshot of the vi I am using but it gives an error unflattened or truncated data. I tried setting the pos offset to start reading after a few bytes but it doesn't help. Any sujjestions? Megan

Hey Guys, I am writing continuous binary data to file and am not being able to write header information like timestamp, number of channels gain etc. I need to update the timestamp everysecond too. Any ideas? Megan

I am getting a little confused here. I am attaching the sub vi I made for the new file format.I am trying to delete the old name and add new timestamp but somehow the old name does not get deleted completely and I see a "2" appended to the stamp everytime a new file is written. Please look into the block diagram and tell me what am doing wrong. PS I am not an expert so please sujjest some simple solutions. Megan

I am using the Format time function but since I am using a continuous acquisition vi the file name keeps getting added with the new time stamp. For example if the initial filename is 20041013140422.dat the next file name comes out to be2004101314042220041013140430.dat and it keeps adding the timestampl. I tried using the functions replace string but it does not work as the very first file does not have a time stamp. I wish I could find a way to update the filename rather than adding new name. Megan

Didier thanks a lot for the sujjestion, I cannot wire it to write lvm file as it does not write at that high sample rate, so I am trying to write a file while appending continuous data to it using the write file vi. Yes I am writing a new file every 8 seconds. Is there a way I can name the file with a timestamp similar to the options in write LVM DAQ assistant?

Thanks a lot Jack, this method does work. Also is there a way I can limit the file size to multiple 10mb binary files? Megan

Hey guys I am trying to create a VI which reads 5 channels at a sample rate of 65536 hz using DAQ Assistant and when I try to write it to a file using Write LVM I get an error message "Possible reason(s): Attempted to read samples that are no longer available. The requested sample was previously available, but has since been overwritten. Increasing the buffer size, reading the data more frequently, or specifying a fixed number of samples to read instead of reading all available samples might correct the problem. Property: RelativeTo Corresponding Value: Current Read Position Property: Offset Corresponding Value: 0." I need continuous data acquisition so cannot read fixed samples. Also it works fine if the sample rate is 16384Hz. Any sujjestions how to overcome this ? Megan