On-board memory nuances in S-series cards

[parmstrong42]

I creating a quick acquisition program using LabVIEW and a PCI-6123 S-series card.  I had a couple of questions regarding the usage of the on-board 16 megasample memory.

1.  Is the entire specified sample memory dedicated to the analog input or is it shared with other portions of the multi-function card?

2.  Is the analog input memory divided evenly among all channels, regardless if every channel is active or not in the given task?  In other words, could I get all 16MS dedicated to a single channel if it is the only one in the active task?  Put a final way, is the number of samples available for on-board storage the total memory installed divided by the ACTIVE channel count?

Thanks...

[parmstrong42]

One additional quick question...

3.  Is there a DAQmx property node where the installed AI memory can be polled for a given device?  I didn't see on in the DAQmx:Device property node, which is where I expected it.

Thanks again!

[Mcdan]

Answers:

1. The memory is dedicated to analog input.

2. The memory is not evenly split between all channels... it will be split only between channels in a given task.

3. The property you are looking for is in the DAQmx Buffer Property node.  You'll want DAQmx Buffer Property Node->Input->Onboard Buffer Size.  Since this is a task-based property, it will adjust the buffer size depending on the number of channels in your task (which I suspect is why it is here rather than in the device property node).

Hope that helps,

Dan

[parmstrong42]

Thanks for the quick response, Dan.

I guess the Buffer property node is more convenient.  It simplified my code since it removed the calculations I had to do to get the same result.

Thanks again,

Paul