Save multiple channels to binary?

I am trying to save multiple channels of analog signals measured using DAQ express. I want to save the waveforms to binary and be able to read them back to re-create the waveforms at a later time. I have tried writing the waveforms to binary as dynamic data and as arrays. Neither seems to work. I am not sure if my problem is how I am saving/writing the data or how I am trying to read it back. What is the best form to use to write the data and how should I read it back?

Hi VCUBME,
LabVIEW is shipping with some good examples that show how to store your data effectively using binary files or datalog files. Please try the "Write Binary File.vi" with the "Read Binary File.vi" for an exaple of storing simple arrays. If you need to store more complex data as for example clusters, then refer to the "Write Datalog File Example.vi" and "Read Datalog File Example.vi".
Have fun!
- Philip Courtois, Thinkbot Solutions

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Help! data manipulation for high speed streaming to disk from multiple boards and multiple channels

I am using Labview 7.1 and have been trying to capture data from 12 channels simutaneously sampled at 2MS/s each and streaming to disk for up to a minute or more. The hardware I am using is 2 x PXI 6133 S series boards with a MXI4 link to a Pentium D 2.8 Ghz machine with 2Gb ram. I have 2 sata drives set up in a raid 0 configuration which should give me hard disk write speed faster or equal to the MXI-4 transfer speed.
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Is there a cleaner way of streaming this data to disk and keeping the channel data separated from each other?, and/or is there a better way to capture and handle the data I need?
I have attached the vi which I have got to consistantly work streaming to disk using the raw 1D I16 format.
Thanks in advance to anyone who can help.
Attachments:
multidevicesync_analoginput_streamtodisk.vi ‏197 KB

Hi,
i can suggest following
Refer to an example VI called as "High speed data logger.VI" in conjunction with "High Speed data logger reader.vi" in Labview examples. Alhrough the logger might be in Tradiditional Daq format, it can be quite easily converted to Daq Mx format to store data in Binary (I32 format) . I have used this for many of my applications and i have found that the data retrieved does not have any "messups".
Why not keep a seperate file for each card? This way, you do not have to load your application with extra process. You only have to acquire and save. After saving in Binbary format, you can retrive it offline, convert it to ascii format and merge the data files of various cards to get one consolidated ascii data file.
hope this helps
Regards
Dev

Save multiple data independent

Hello,
Can you tell me if it is possible to save data from multiple channels, each channel with a different save trigger?
I have a cycIing machine and I need to record data from 6 channels, (that are not synchronized - different part of cycling for each channel), and to save data just when the data passed a certain value, for an among of time.
Please tell me if it is possible in Diadem, and what blocks should I use.
Thank you for the support.

Hello Marse,
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Greetings
Walter
Attachments:
Test.DAC ‏81 KB

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thx B
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End Sub
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Hi rvillalta319,
Sounds like you'll need to adapt your code to use both a for loop and some implementation of the GroupCount variable (or ChannelGroups.Count) as seen here:
http://zone.ni.com/reference/en-XX/help/370858K-01/varoff/groupcount/

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Data acquisition from multiple channels.

Hello
Right now, I am able to acquire the signal from a single load cell and display it.But I would like to know of how to acquire acquire signals from two load cells simultaneously.I am using Labview 6i and I am using AI S-Scan with AI config to acquire the waveform.It would be of great help if you could suggest a simple method to acquire the signals.
PS: Please find the attached file used for acquisition from a single load cell.
Looking forward for your reply.
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Attachments:
test 4.vi ‏102 KB

Hi Manasa,
If I understand what you are trying to do, it is relatively
straightforward to configure your application to acquire data on two channels.
I was unable to run your vi as it was missing some of the subVI’s
from your application. However, your
attachment was sufficient to see what you are trying to do.
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1.
In the I/O Channel Constant, you can add
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you would put 0:3 in the constant (see attached screenshot ChannelConfig.jpg). To scan the first and third channel you would
put 0,2.
2.
The AI Single Scan VI will now read from
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array using the Build Array VI. It can
then be plotted in a waveform graph. (see attached screenshot ReadtoGraph.jpg
and WaveFormGraph.jpg)
Just a few notes about “simultaneous” sampling:
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between the various input channels and the Analog to Digital (A/D) converter
creating a very small delay between each channel (usually ms range or
smaller). NI does make several data acquisition
cards that can perform true simultaneous sampling, meaning that there is an A/D
converter for each channel.
For the large majority of applications, the small delay
between channels is negligible.
Jared T.
Attachments:
ReadtoGraph.JPG ‏21 KB
ChannelConfig.JPG ‏288 KB
WaveFromChart.JPG ‏61 KB

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Dear Sir
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Hello,
I am writing a driver for the M-series NI PCI-6255 for QNX. I have downloaded the MHDDK and have all the examples working. I have also enhanced the examples to do interrupt handling (e.g. on AI_FIFO interrupt or DMA Ring Buffer interrupt). My ultimate goal is to write a driver that I can use for closed-loop control at 500 Hz using all 80 channels of the NI PCI-6255. I may also need to synchronize each scan with a NI PCIe-7841R card for which I've already written a driver. I want an interrupt-driven solution (be it programmed I/O on an interrupt or DMA that generates an interrupt) so that the CPU is available to other threads while the 80 analog inputs are being read (since it takes quite a while). I also want to minimize the number of interrupts. Basically, I will need to collect one sample from all 80 channels every 2 milliseconds.
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Save multiple channels to binary?

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