12-08-2009 09:31 AM
Hi. I'm using Labview to interface to a PIC16F450 (RAW). When the PIC sends
data (2 bytes) to the PC every 100ms
everything works as expected. This data is graphed inside the loop shown below. However if the data rate is increased to a packet
every 6ms problems occur. The graph is no longer in sync with the actual data
being sent. The data in labview lags that being sent by the PIC. If the part is
powered off the graoph continues to update for a few seconds.
Is the following method for acquiring data valid?
What is the maximum data rate the VISA Get Usb Interrupt Data.vi? How does
VISA buffer the data? I saw another thread on this but it didn't answer my questions.
12-08-2009 09:42 AM
Hi!
Why you use Timeout = 0 ms if waiting on event? Where is the graph in the loop? You should not use a graph inside this loop.
12-07-2010 12:35 AM
Hi, I am using the same way as you to get USB interrupt data, and I am facing the same issue as you (some data missed or wrong).
And the wait time is already set to 20ms or larger, no graph in while loop either.
12-08-2010 04:55 AM
Hello mapleaf9989,
This thread seems to be over a year old and the original author might have unsubscribed by now.
For a better chance of getting a response, please create a new posting with your VI and the errors your are receiving. The forum users, including NI Application Engineers, will have an easier time spotting it.
Regards,
12-08-2010 06:39 AM
Hi,
I haven't unsubscribed. I abandoned the approach I was taking above. Instead I used C++, NI VISA and a third paty graphing library which I found far easier to debug. I was able to get the performance and graphing options I required that way.
12-08-2010 07:03 PM
Hi, I don't understand very clearly. Would you mind share a little on your diagram?
I got stuck in the Labview program now.
Thanks a lot.
12-10-2010 05:19 AM
I didn't use Labview. Unfortunately I can't help you with that. Maybe you should start a new thread and post the VI you're currently working on. Sorry I can't help.
09-03-2015 02:43 PM
Hi
I know this post was really old but would you have a sample code in C++ how you got data out from your device? I am having same issues as you had with your device. Please help. Thank you.
09-03-2015 03:24 PM - edited 09-03-2015 03:25 PM
This time, he probably has unsubscribed... It's been 6 years since the original post, so either way, OP probably doesn't have the source code handy anymore. I would suggest posting your issue as a new question in the relevant forum.
Cheers
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