waveform generator

[Roxanne]

Hi,

I am using a 6551 waveform generator, generating on 14 outputs and simultaneously capturing on 6 inputs. All of a sudden all captured waveform are zero, I tried restarting LabView, and later restarting the computer, seems the card does not seem to capture anything.

Any ideas as to what might have gone wrong?

Thanks

[simply_me]

Hi Roxette,

Did you look into MAX (Measurements and Automation) to see if the card is still defined there?

A

[Roxanne]

Yes, the card seems to be working fine according to MAX. I am using an example for simultaneous generation and acquisition from NI:

Dynamic Generation and Acquisition-Demo.vi

with minor changes:

1) Using an .hws file to generate waveforms as opposed to the waveform created in this example VI.

2) Using different sets of channels for generation and acquisition.

However instead of the clock that I am generating (and routing to an acquisition channel for test) I am getting flat lines.

In other words it seems the card triggers once only.

I have tried "Pattern to Match" of all 'x' instead of 0 or 1. Same issue.

[simply_me]

Have you tried to generate the signal in a loop?

Can you post a picture of your block diagram?

[Roxanne]

[simply_me]

So, you should setup the connection before a while/for loop (e.g. create channel), acquire the signal in a loop (get signal), and then stop and clear signal. That's the general schematics you should follow.

As it is now, you only acquire N samples once.

[simply_me]

For example, I did this vi yesterday.it's a basic vi to adjust gain, but it follows the same structure- initialize, acquire, close/clear

Obviously, if you want more features such as save file you should decide if you want to do it in the loop or out of the loop, etc. 

[Roxanne]

So, generating the channel for acquisition and the acquiring data has to be in a loop? But if the intention is to generate and acquire at the same time, then both generation and acquisition have to be in a loop.

Do you have any examples for HS-DIO that you can send me please?

[simply_me]

No, you want to generate a channel/initialize out side of the loop in most cases. Just like I did in my vi-- created 2 channels outside but read them inside the loop, and stop-clear when done outside of the loop.

Is this example helpful?   http://zone.ni.com/devzone/cda/epd/p/id/2963

[David-A]

Hi Roxette,

You may want to take a look at the our Getting Started with NI-HSDIO.  Hope this helps!

David A.