09-05-2012 08:22 AM
I have been chasing a problem with a piece of equipment of almost a year. Please provide meaningful help.
I am a test equipment vender. I have a shell program that I have been using for over 10 years in other equipment without any problem. My shell is created in VB.net 2005 using NI measurement Studio 8.1. The machine in question has:
DAQmx 9.4
9178 rack with:
9201
open
9425
9425
open
9472
9472
9472
The application will write to the DO (9472) several times a second.
It appears to be a memory leak. I have tried many things to alleviate this problem; the computer will only run for about 2 days and then it crashes as the memory usage climbs. This is the only message showing up in my log files:
NI Platform Services: The requested memory could not be allocated.
Task Name: _unnamedTask<0>
Status Code: -50352
With in one second this message is written to the file 635 times.
this is the main code that writes to the hardware
Try
digitalWriteTask.WaitUntilDone()
writer.WriteMultiSamplePort(True, DOWrite)
Catch exception As DaqException
WriteToTesterLogFile(exception.Message, LogTypes.Software, True)
End Try
writer = Nothing
Thank you for your help,
Jeff
09-05-2012 02:10 PM
Hi Jeff,
This sounds like it may be CAR #327313: "Host PCs that use CompactDAQ can crash after long periods of continuous use", which was fixed in NI-DAQmx 9.5. In NI-DAQmx 9.4, uncommitting a CompactDAQ task leaks 20 bytes of kernel memory.
If you can't upgrade to the latest version of NI-DAQmx at this time, you may be able to work around the problem by calling digitalWriteTask.Control(TaskAction.Commit) once and reusing the same task over and over again.
Brad