VB 2005 MStudio 8.0.1 Memory leak

[Crusader]

Hi,

I'm having some problem with MStudio 8.0.1 and visual basic 2005. I've done an application that read AI, DI and set AO, DO with some MStudio components. My application have a memory leak.

I've track down the memory leak to the function were I read AI and DI and the function were I set AO voltage. We are using a PXI-6229 for AO, a SCXI-1004 for AI and SCXI-1162HV for DI.

I will attach the two functions I'm using to acquire the data in a small application I've made for you to help me with this memory leak. Once you click start in this application, the memory will increase, slow down a bit and will continue to increase time over time.

Thanks for your help, and sorry for the French note in the application.

[Jesse_O]

Hello Crusader,

I have taken a look at your code, and it appears to be ok.  However I am seeing the similar behavior to what you describe.  I will look into this further and get back to you when I have more information.

Regards,

Jesse O.
Applications Engineering
National Instruments

[Crusader]

Thanks, I will wait for an answer, since  we can't use correctly our application using this code since the application is hugging all the computer memory after 1-2 days of 24h running.

[Jesse_O]

Crusader,

I have taken another look at your code, and I have been able to run it for a while without any increase in memory by removing the start and stop for each of your tasks.  Since you are only performing software timed i/o you do not require these start and stops.

Once you comment them out everything should be ok.  For example make this code:

ReadAITask.Start()

Data = AIReader.ReadSingleSample()

ReadAITask.Stop()

this:

Data = AIReader.ReadSingleSample()

Regards,

Jesse O.
Applications Engineering
National Instruments

[Crusader]

Hi,

I've tried your solution and it worked. I don't really understand why, but it worked.

Thanks !

[john Lanz]

I am having a similair problem. I have NOT tried removing the start and stop. See the message "Why does EndReadMultiSample cause the daqmx dll to run out of memory". The symptom sounds the same. I am using EndReadMultiSample though.

[bilalD]

Hello Crusader.

I tried this out and it looks like the original memory leak described in this thread no longer occurs in DAQmx 8.3.1