LABVIEW VIs STRUCK RANDOMLY

[rtrtre]

Hi,

I would like to receive few inputs about the issue that I am facing in My Project.

Station Details:

                      Intel[R]Xeon[R] CPU

                      W3530 @2.80GHz

                      2.80 GHz, 3.00 GB of RAM

LabVIEW Version: LV8.6

We have developed two VIs [say A.vi & B.vi] & We are using Notifier to communicate between VIs.

 Functionality: A.vi communicates B.vi in a loop of 50,000+  iterations by using Notifier. 

                          At each loop, 

                                i)   B.Vi performs SMBUS Write & Read operations with custom DLLs

                                ii)  UI Tree Update will also happen.

                           We have configured Notifier timeout as 10secs.

 Issue:  During 50,000+  iterations, B.Vi is getting struck at somewhere for more than 2hrs. At that period, we expect A.vi to throws

             Notifier timeout [as Notifier timeout was configured as 10secs] 

             But suppressingly, both B.vi & A.vi hangs at that time. 

Note:T

here is no Delay or Infinite loop in B.vi which causes B.vi to hang.

Approaches taken to figure out the Issue:

  1. We have logged Timestamp between actions in both A.vi & B.vi & we came to know both the VIs got struck at that period.

      We are guessing LabVIEW may hang at that period.

  2. We have avoided memory building & removed the unwanted code from both VIs. But still we are facing the issue at randomly.

 We are trying to understand the following things:

        1. Even if B.vi hangs why A.vi does not throws any timeout error.

        2. Based on debugging, we found that LabVIEW gets freezed at that time due to either SMBUS DLL or other actions.

        3. We have figured out there is no delay / issue in SMBUS DLL.

Possibilities for the Issue may be:

1. Memory Leaking / Memory Overflow: We have noticed that while running the VI, the memory occupied by LabVIEW is:

                                                                      179,300KBytes.

                                                                      During the execution also, LabVIEW occupies more or less same the memory.

2. Data BackUP Software:                           We have disabled the DataBackUp Software in the System. But still we are facing the

                                                                       issue.

 Please provide your suggestions of how to debug this further to figure out the issue.

Thanks,
Saranya 

[altenbach]

• What is "getting struck". This term is usually used in combination with lightning.
• How long is "more than 2 hours"?
• Does it recover soon after 2 hours or does the condition typically continue forever?
• What is your operating system?
• How do you know there is no problem with the dll?
• How is the dll call configured? does it run in the user interface thread?
• Have you tried a newer LabVIEW version?

[DFGray]

It sounds like you have an intermittent race condition leading to a deadlock.  Unless your computer does not have much RAM or your memory is very fragmented, the LabVIEW memory usage should not cause the issue.  You can fragment memory by repetitively using lots of build arrays, concatentate strings, or other array expanding nodes.  There are usually alternatives.

However, we are shooting in the dark unless we can see your code.  Can you post some or all of it?

In the meantime, if you want to find out exactly where your code is hanging, and you can't use the normal LabVIEW debug methods, try this one.