Resources in use on USB6229

[paul.ostro]

Can anyone help with finding out which resources are used by particular NI-DAQmx ANSI C calls, please? In particular I would like to know if the use of a 'timeout' in Read or Write calls uses one of the Counters on my USB-6229 card. However, in general, I wonder if there is some structure or property that has a list of the resources in use at any particular time? 

Thanks

[Tom.]

Hello Paul,

When you say 'resources' what do you actually mean? Do you mean the channels or tasks related to a particular board? Or do you mean for using a timeout function for an AI Read will your counter line be used to make this time measurement?

Tom | NIUK

[paul.ostro]

Hi, Tom. Thanks for replying. (I'm new to DAQmx, sorry if I wasn't clear.)

The latter - if I ask for a timeout in the timeout parameter of - in my case - a Digital Input Read, does DAQmx use the onboard counter (dev/ctr0 or dev/ctr1)to determine if the read times out. If it does, then I have one less counter to use as a sample clock for analogue input and output tasks happening at the same time.

I could try it out and see if the task is rejected, I guess, but I wondered if it was documented anywhere - or if there was a DAQmx function which returned the physical devices (are they called this?) in use for a given task (dev/ctr0, dev/ai0......etc).

Paul

[Tom.]

Hello Paul,

The answer is no, the counter lines arent referenced for other acquisition timeout fucntions.

Cheers

Tom | NIUK

[paul.ostro]

Thanks, Tom. That is really useful.

Ummmm....out of curiosity, how are the timeouts done? Is there any limit on the number of timeouts 'active' at one time. For example, if I have more than one task running concurrently, each with a timeout in use, is there any limit?

Paul

[Tom.]

Hello Paul,

There is no reason why you can not have as many timeouts as you want occurring simultaneously. Explaining how we make our functions work will essentially be releasing our Intellectual Property (IP) and so I can not really provide an answer on this.

Cheers,

Tom | NIUK