Problem in accessing labview shared variables in TestStand when machine IP changes

[kbsave]

Hi All,

We have a system which includes a PXI RT where our simulation runs. We are using an Interface.vi which contains shared variables to get the data from PXI to TestStand(Host and PXI connected on ethernet). The shared variables are located on the same Host PC where TestStand is installed.
As such everything works fine. Problem comes only when we change the Host PC. If we use the sequence and Interface.vi on another machine (different IP), the shared variables on old machine get updated instead of the new one. I have used Deploy Library Step which points to the shared variable llibrary on the host.

Please let me know if I am missing on something. Also if there is a better way to access data from PXI RT please share it with me.

Thanks in advance,
Kaustubh

Message Edited by kbsave on 05-08-2008 11:54 AM

[kbsave]

Hello Guys,
Is there any remedy to this problem? Or have I asked this question in wrong board?
The Interface.vi works perfectly when used in LabVIEW project environment the problem comes only when it is called from TestStand. So I guess it is appropriate to ask this question in TestStand board.

Regards,
Kaustubh.

[Hillary_C_E]

Hi Kaustubh,

Have you tried hosting your shared variables on your PXI? When your code is running on your PXI, it is probably still sending data to your old host computer. However, if you host the shared variables on your PXI and then have your LabVIEW code reference them from the PXI you should be able to use your TestStand and LabVIEW code on any host computer that can interface with the PXI.

[kbsave]

Hi Hillary,
Thanks for your reply.
Actually I have already tried that. But if I do so, there is no problem when the host machine is changed. But if I change the PXI (with different IP) the variables in old PXI are updated and not in the new one 😞 . And also there is no step is TestStand which can deploy Shared Library on PXI. That is why we have kept the library on host. But even with Deploy Library Step shared variables on host are not updated.
I would like to know if there is any specific way to use the Deploy Library step?

Regards,
Kaustubh

[A_Ryan]

Hello kbsave,

I have a couple of additional questions for you:
1.  Is the application you are deploying an executable?
2.  After you change the Host PC are you redeploying the shared variables?
3.  How are you able to determine that the old Host PC gets updated and not the new one?
4.  Does this same problem still happen if you are working the development environment?

You may have already seen this, but How Do I Call a LabVIEW VI That Contains Shared Variables From TestStand is a useful link.

[A_Ryan]

Hello kbsave,

In the Using LabVIEW with TestStand manual, under Using an Aliases File (in section A-3) is some additional information that you might want to consider in your application.  Especially, because it addresses why LabVIEW must resolve conflicts associated with target name stored in the network path for the shared variable.  This information also might explain why you are having some issues trying to communicate with a particular target or host.

[kbsave]

Hi A_Ryan,
Thanks for your reply and sorry for the delay in my reply.
Answers to your questions in previous post:
1. Is the application you are deploying an executable?
Ans: Yes. It's an RT Executable.
2. After you change the Host PC are you redeploying the shared variables?
Ans: Yes. I have included the Deply/Undeply library step in my sequence.
3. How are you able to determine that the old Host PC gets updated and not the new one?
Ans: We have 2 setups, each consisting a host PC and a PXI. I transfered my code and sequence from one setup to another and it was not showing any error and also was not working. Them somebody turned OFF the other setup and it was started giving the error that shared variables are not found (the error message was showing the IP of old setup).
4. Does this same problem still happen if you are working the development environment?
Ans: Yes. The same issue comes in Development environment as well.

I will go through the manual and let you know if I am missing something or doing something wrong.

Thanks & Regards,
Kaustubh.

[Hillary_C_E]

Hi Kaustubh,

When you moved your Real Time project to the new system, were you able to run your code there properly (independent of TestStand)? When you move your project are you redeploying your Real-Time executable to the target before you run your TestStand code? If you use the NI Variable Manager to remove all variables from your original host and your newer host and then deploy your Real-Time executable on your new host, do you still see the problem?

I'm curious if you encountered anything from reviewing the manual.

[kbsave]

Hi A_Ryan, Hillary,

The solution provided in the manual worked 🙂 🙂

Finally my two setups are isolated and they are independent of machine IPs.
I have copied the project aliases file to LabVIEW directory.
I have also changed the machine IP present in the aliases file to "localhost". Now this one single file works on all machines.
Thanks to both of you.

The problem is solved but still answers to Hillary's queries:
1. The code works perfectly within the LabVIEW project environment.
2. We are redeploying the exe to target when we move the code.
3. The problem persists even if we manually undeploy the variables from variable manager and redeploy it again in the new host. The VI called from TestStand still points to old machine variables.

I think it always looks for the LabVIEW.aliases file.

Thanks a lot for your support.

Regards,
Kaustubh