memory problem & multirecord acquisition

[DeBli]

Hi,

I have a pxi 6562 to test chips in my lab. I have asked various questions related to this problem in previous threads, but now wish to post the entire problem to see if anyone has any suggestions.

The first problem is a memory problem, infact in a first version of my application (see attachment biochip1) i generate and acquire a number of samples that for high N (more than 😎 give me memory problem because the application need to create a waveform data with more than 2 million sample, in this case i don't have problem in the acquisition because i have the entire output waveforms (called B0 & B1) and based on trigger i collect via software the necessary data to do digital correction and DAC conversion.

To solve the memory problem i realized a second version of application (attachment biochip2) in which i modify the approach: i don't generate a long waveform but i generate one smaller and i repeat it 2^N times (the first is different from all others because i need to send a pattern to my chip) by the driver "niHSDIO Configure Generation Repeat"  but in this case i have an acquisition problem because for each of this repetition, except the first, i need to collect 11 samples of B0 & B1, one for each front edge of trigger signal i generated, to do digital correction and DAC conversion but i don't now how can obtain it...any suggestions??

I hope that  I explained well the problem but if anyone have some doubts can ask me...moreover i attach a version of my application without pxi drivers so if anyone want to help me but haven't this hardware can try the application operation or to better clarify it. thanks 

Message Edited by Support on 09-11-2009 08:49 AM

[lucius]

Hi DeBli,

it is not clear to me which is the acquisition problem you have in the second case...

Can't you just set the acquisition exactly as in the first case, independently from generation?

Cheers,

Lucius

[DeBli]

thanks for your reply sorry if i answer so late...i think that with the second solution there would be a synchronization problem. Infact when i tried a simple multirecord acquisition i observed a shift of the record but this is not tolerable in this application because i need that for each of 2^N samples generation & acquisition be  synchronized...what do you think about this?

ps. i noted that you are italian so what do you think to transfer this discussion in the italian subsection,too? there will be more easy to me to clarify the situation 🙂

[lucius]

Hi DeBli,

if you want you can move the discussion to an Italian thread, but actually I suggest you to continue here, because English boards are read worldwide and you have much more visibility here than in Italian boards. Anyways it's up to you.

Speaking about your problem, have you tried using the "Configure Generation Repeat" in continuous mode, such that the generation is hardware timed allowing you to synchronize the acquisition by setting a continuous read and sharing a pxi trigger line?

Regards,

Lucius