Start acquisition and display chart/graph, then use trigger to capture data. Need pre/post trigger scans.

[atwork]

What I am looking for here is to be able to start reading the channels connected to the board (PCI-6071E) and be able to monitor a trigger channel to obtain pre/post trigger scans.

I tried the examples that come with LV6.1 but I haven't been able to find a solution. We currently have a solution that uses software buffering,ei global/local variables, but I would like to use hardware buffering as it's done on the many examples LV has.
Is there anyway to see the acquired data as it waits for the trigger? The only example that comes close to what I need was "Cont Acq&Chart (buffered).vi", but I don't know how to use it. Particularly the Clock.
Thanks,
Atwork

[Spencer S.]

Greetings,

Unfortunately, it is not possible to read the acquired data before the trigger occurs. Using a software buffer, as you mentioned you are currently doing, is a good way to accomplish this task. Are you running into speed limitations?

Spencer S.

[atwork]

Hello Spencer,

No, I�m not running into speed limitations. The problem lies in that the current solution I have was developed before me and it was done in LV5.0 and the way this was done was by using a multitude of local and global variables, (more than 500 nodes per variable), to capture pre-trigger data. I am now using LV6.1 and I would like to make changes to the existing code using LV6.1 but I can't because LV6.1 doesn't like to see more than 500, (more or less), nodes.

Since you are saying that it isn't possible to read acquired data before the trigger occurs, I will have to come up with a software buffer that could be used to allow what I need. I am thinking of using the QUEUE VI's. I would set a pre-trigger buffer of the required size a
nd wait for a trigger on a limit previously set, when this is satisfied then start saving data from that point on.

Any suggestions?

Thanks,
Atwork