data record with pause in the middle

[jackedi]

hello

i'm using labview 8.6

i'm trying to make a code that will allow me to record an analog output channel (of DAQ 6259).

my problem is that i need to record the channel alternately (for example record for 30msec stop for 200msec record for 10msec stop for 50msec and so on), and i cant have any delays between my record/stop command and the execution of the command (at least not from the recorded data point of view).

i tried to enter the data to an array inside a while loop and my while loop is inside a case that choose if it's record time or pause time.

the problem is that if i do that the loop control is not that efficient and the data is not sequential.

does anyone have any idea how can i do this correct?

[johnsold]

What determines when the start and stop commands occur?  How does the software get this information?  The times you suggest are much too fast for a human user to generate.  Are they predefined or on an analog or digital input channel?

In any case I suggest that you set up to acquire the data continuously and then extract the sections you want to record.  A Producer/Consumer architecture might be appropriate.

Lynn 

[dark7flame]

You could also have a 2-sequence inside a loop, with the time (in ms) determined by you entering numbers into 2 different controls.  You could also control how many iterations using external controls, which will affect how long the entire data gathering section is viewed.

Please be a little more clear on what you actually want to do.

[Mark_Yedinak]

I would recommend implementing your data collection inside a state machine. This would give you the flexibility to control your data collection in any way you want and allow you to extend your control in the future. I would avoid using sequence frames to control your operations.

Message Edited by Mark Yedinak on 10-13-2009 01:19 PM

[cirrusio]

Along John's line - could you give more information, because without the details it is hard for anyone to provide a good recommendation.  If you data acquisition is triggered off a user event, I would be hard pressed to believe that you will ever get the kind of performance that you are looking for.  But, if the  acquisition is based off of a timing diagram, I think that there might be ways to efficiently collect the data at the intervals you are seeking.

Matt 

[jackedi]

i'll try to be more specific:

i have an algorithm in matlab i suppose to run in labview (with math script).

the output of the matlab is int 16 [] is suppose to transmit  by analog output of my DAQ.

i also need to record this output.

the system that read the output works in millisecondes resolution.

between one iteration of the algorithem on another iteration i have a 200msec setup time that i dont want in my record.

after i run this test i want to be able to run my record to the system without the setup time, that means i need the data to be sequential and not to have even 1msec delay between one iteration and the other.

thank you for your help 

[cirrusio]

Can you post the code you have thus far?  Or possibly provide the signal you are wishing to output for D/A?  Thanks, Matt