Semaphore

[R_J]

hi

I am just trying to learn the use of semaphore. in my application i am making a VI just same as the inbuild example given in Labview. When I stopped the Main VI  then the two sub  vi were also stopped but with an error message code : 1111 ,  description : Release Semaphore.vi.

I am not getting the reason for this  error message

I am attaching the code.Please help me on this issue.

Thanxs

Raman 

[pincpanter]

You can get the reason with Help->Explain error menu item and writing the error code into the proper control. Error 1111 means that the code is trying to release a semaphore that was not acquired. I can't say more because I only have LV 7.1

Paolo

[R_J]

Hi

Thanxs for reply. But the attached zip file semaphore.vi is same as given in the Labview help Semaphore with SudVIs. I am not able to find the bug. please help.

Raman

[pincpanter]

The example is working well for me (7.1). Did you change something in the example vis? If you did, please repost all vis saved for 7.1 (File->Save with options): I didn't install LV8 yet.

Paolo

[R_J]

Hi Paolo

Thanxs for reply.

You just check the error output of both the sub VIs .For me it is showing Error having code 1111

Raman

[Chris_Cilino]

Raman,

I can see why this example is so confusing. It is actually working "correctly", that is, it is working according to the way it was designed. The way that the program shuts down is by detecting an error. If you look in the example, you'll see a comment that says "Destroy semaphore (this will stop the subVIs)". This works because once the semaphore is destroyed, it can no longer be locked or unlocked. This generates an error in the 2 subvis which are programmed to stop the while loops on errors. You'll actually notice that an error occurs at both the acquire (error 1)  and release semaphore vis (error 1111). This is very much by design, although very confusing.

Chris C