number of sample generate and acquired over limit HSDIO 6552

[engwei]

Hi all,

I m currently using HSDIO 6552 and I have run a test pattern with number of sample 16M samples. An error prompting out to indicate that there is not enough of memory to hold such big number of samples.

The problem is not about the size of waveform but the number of sample acquired from the result. There are a few large number of repeat, like "repeat 60000" in the script. 

And, this test pattern have to run continuosly and then display the generated and acquired signal from the DIO. Any idea about this ? Any method to get the "full" result without interrupting the running test ?

Pls let me know if anybody here has any opinion to solve this, or any reference link I could refer to.

Thanks in advance for your time and help.   

[Lee.P]

Hi Engwei,

You are acquiring from 6552. How many channels are you using?? Can you show me the vi that you used??

You may want to refer to the link below that has an example on using HSDIO.

http://zone.ni.com/devzone/cda/epd/p/id/5271

Regards

Lee

Applications Engineer

NI ASEAN

[engwei]

Thanks for your reply. 

I m using the example from NI to generate and acquisite data in multicard mode.(attached)

I hv roughtly surf the example from NI-HSDIO Stream to Disk (Acquisition) Using Win32 File IO article. 

The data will stream to PC, but now I am using "hardware comparison" to compare the acquired and expected data.

So,  if I use the method from "NI-HSDIO Stream to Disk (Acquisition) Using Win32 File IO" how could I compare them ? Any "SampleErrorBacklog" similar function for ease of error info reference ? any idea about it ? 

Thanks again for your time. 

[Lee.P]

Hi engwei,

There are a couple of information I would like to get from you.

1. How many PXI-6552 are you using?? Which chassis are you using??

2. You mentioned that when you generate 16M samples, there is an error prompt up indicating not enough memory to hold such large number of samples. Can you give me a printscreen of this error?? Are you using the example you attached in your previous post when you encounter this error??

3. You also mentioned that there are a few large number repeated, like "repeated 6000" in the script. From the example you attached in your previous post, there is no script. What script are you referring to??

TClk is used when we want to sychronise multiple devices. If you are using only 1 PXI-6552, I think you do not need to use TClk.

You want to look for information on continuous generation and acquisition. Please correct me if I am wrong. I have attached a few links below. You can find example and information on how to achieve that. There is also information on how to use script on PXI-6552. I hope these are useful.

Hardware Compare with Scripting on a National Instruments High Speed Digital I/O Board

Advanced Features of High Speed Digital I/O devices : Scripting In High Speed Digital I/O Boards

Advanced Features of High Speed Digital I/O devices : Hardware Compare

Regards

Lee

Applications Engineer

National Instruments ASEAN

[engwei]

Thanks for your advise again.

1. How many PXI-6552 are you using?? Which chassis are you using??

I am now using 3 PXI-6552 (so, I need to use TClk) , Chasis NI PXI-1036

2. You mentioned that when you generate 16M samples, there is an error prompt up indicating not enough memory to hold such large number of samples. Can you give me a printscreen of this error?? Are you using the example you attached in your previous post when you encounter this error??

Ya , the error is indicating too large number of samples. I will attach it once I reproduce it in lab. Ya, the error can be reproduced from the example attached. 

3. You also mentioned that there are a few large number repeated, like "repeated 6000" in the script. From the example you attached in your previous post, there is no script. What script are you referring to??

Em. Let assume the sript is like:

script Myscript

repeat 6000

wfm0

end repeat

end script

wfm0 is 1,000,000 lines (1Mb) and over 60 Channels (there are 50 Channels involved in bidirectional -drive and strobe and 10 Channels with drive only.)

I believe the error is due to large acquisition size. (Which is my problem stated in this post)

By the way, my another problem is, I can only acquired 4096 number of error samples (max) due to only 4096 bit buffer to allocate error bit. Any idea to acquire more error samples without interrupting the generation and acquisition session ? Let say acquired first 10,000 error samples ?

Thanks for your time. 

[ChrisNI]

Hey engwei - a quick note about the 4096 error samples.  These errors are stored in a FIFO - if you can fetch the errors out of the FIFO fast enough, you can capture the error information indefinately.  Once the FIFO gets full, it no longer accepts any more, even if you empty it.  The driver will not produce an error, as this is not necessarily an error condition - the stimulus will still continue, and the response will still be analyzed (and captured, if you've requested it).  The "number of sample errors" and "number of samples" attributes continue to increment.

Have you been able to get things working with a smaller sample size (i.e. less than 500kSamples) - even our lowest memory board would easily handle that amount of memory.  I wanted to make sure that you've gotten that far.  If you've still got errrors with that amount of memory, you might want to focus on that area first, and then move to the larger memory case.

Hope that helps,

Chris

[engwei]

Hi,

Thanks for the advices from you all. 

Ya, I have noticed the info, as what you stated in "a quick note about the 4096 error samples". This is why I emphasize about get all the error samples (>4096) without interrupting the session.

 Ya, for smaller size, no problem. Everything running smooth. 

The problem only comes

1. when large number of sample, which I may need to stream it to PC as suggested in this post.

2. and when >4096 error sample, have no idea on how to acquire more error info. 

Thanks. 

[engwei]

Erm ..just to update here ..

from my last post ..

1. when large number of sample, which I may need to stream it to PC as suggested in this post.

Basically, PXI-6552 can generate infinitely, as long as the waveform+script memory loaded to the it is less than 8MB.

For my case, to acquire sample which is larger than 8MB, I will use multiple record to generate a trigger from the script and acquire only after the trigger.   

2. and when >4096 error sample, have no idea on how to acquire more error info. 

Have to fetch the error the clear it.

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