Custom Shared variable Real Time

[Simbani]

In LabVIEW 8.0 and RT 8.0 I am using without any problem a custom shared variable that is a cluster of five DBL. However, after having created a custom shared variable of the setpoint profile (array of time and set point value pairs PID setpoint Profile.vi) I get the error code number -1950679035 (ni_tagger-lv_Write) LabVIEW : Hex 0x8BBB0005) The shared variable does not exist. However, it exist because I have created. I have mass compile the program, but it has not fixed the error.

Does any one knows the reason of the error ?

Simbani  

[The_Seeker]

Simbani,

This is interesting -- I experienced the same error while trying to use a cluster. As a work-around, I tried flattening it to a string and passing the string. This seems to have solved that problem, and although it is a bit clunky, I can live with that.

More disturbing however, is that now I'm seeing that same error code and message (-1950679035) again, but this time with a single i32 shared variable. I've tried renaming it, changing the type to DBL, and a few other things, but for some reason, this particular variable doesn't seem to exist -- at least as far as LabVIEW and the Shared Variable manager are concerned.

What's weird here is that I have several shared variables of various types that all seem to work. This particular i32 was created at the smae time as the others, it shows up correctly in the Project with the others, but it's just not working. I usually like to think the mistake is my own (--then at least, there is a chance I can fix the problem). However, in this case, it really looks like a bug in the Shared Variable implementation.

Of course, I would be very pleased to find out that the problem has something to do with what I'm doing...

Anyone else noticing a similar problem?

-- D

[The_Seeker]

Simbani,

After some additional experimentation, I noticed that the Shared Variables causing the errors appear to have names ending with a space character, that is," " (no quoatation marks, just the space between).

In my case, the problem name was: "ExposureTime ". Changing it to "ExposureTime" (without the trailing space) did the trick. (Incidentally, I tried changing the name, but apparently I didn't delete the final space.)

Anyway, check the name of your variables. Make sure there is not a space at the end. If there's no space, try different names as there may be other characters that may cause the same problem.

Hope this is useful.

-- D

[Simbani]

D,

Thanks for your information.

I have expent quite a long time, more than 80 hours trying to solve the problems a face daily with the behaviour of the shared variables and I am afraid, I am unable to overcome the problem.

If I am not mistaken, although, when connecting directly the PC with the Target you should use a crossed ethernet cable, it seems this kind of conection does not work. I think it is better to use a normal ethernet cable and a hub between the PC and the Target. I have tried this connection and it works, but, it does not correct the errors of the shared variables. Among other errors with shared variables I get quite often the -1950679035 and the -1950679022 

Is there anyone who has got a good experience working seriously with the shared variable ?

Simbani

[The_Seeker]

Hi Simbani,

I have had similar problems with the ethernet x-over cable in the past. These seem to have cleared up for me with LV 8.0, but it sounds like the problem still exists for you. In any case, ethernet hubs and switches are reasonably cheap these days...

About your shared variable problems -- in addition to the space character problem, I've found that creating a new variable and deleting the old, problem variables usually works to overcome -1950679035 errors.

On a different note, I'm wondering if you are using a localized (non-english) version of LabVIEW. Since the problem I had was related to a specific ascii (or perhaps unicode?) character, maybe there is also some issue with specific characters in other language versions of LabVIEW (and/or Windows). Just a thought...

As a work-around, you might try creating new shared variables and assigning them different names to see if this helps.

Cheers,

-- D

[Simbani]

Hi D,

I am  using the standard american language LabVIEW comes with and I use Sky Link NET 1008 8-port-N-Way Fast Ethernet switch (100 Mbps) with non crossed ethernet cables. By the way, I wonder whether 1000 Mbps will siginificantly improve the performance or not. Any experience?.

I have delated the variables in the host and created them in the target, then the values passed correctly and I hot not any error. This was done with the Firewall enable.

My Windows XP Professional comes with Service Pack 2 and as default the Firewall (Control Panel) is enable. After having disable the Firewall, I have been able to create and use the shared varaible in both, the host and the target without any problem.

Now, I´ll have to use quite a lot of shared variables of practically all types and will see how the bahave in a medium size program.

Simbani

[Nopo]

Hello guys,

I have problems as well with the DSC shared variable visualization, when I run a VI under a project to read data from a Modbus module. The error code: -1950679035. Shared variable doesn't exist, appears in my screen, despite the fact that the variables (DBL) are well defined in the project library.

Until now I have tried:

- Rename the variables, creating new variables.

- Disconnect the windows xp firewall.

- Checking the ethernet default connection.

- Re-install the software package (LabView and Modbus Utility).

- Create a new VI only to visualise the variable.

Any ideas why do I have this error code?

Thank you,

Nopo

[Wayne.C]

I had problems with network shared variables while targeting a cFP-2120.  Turned out that the problem was caused by the cFP-2120 and its need to use a RT FIFO for the variable.  RT FIFO's are not compatable with a cluster data type.  Not sure how this relates to other RT targets.

[rex1030]

Since you guys have tried all that stuff, try everything on here:

http://digital.ni.com/public.nsf/allkb/6E37AC5435E44F9F862570D2005FEF25

I found that setting all the DNS server fields to 0.0.0.0 makes a huge difference. Also, as dumb as it sounds, I get a lot of unexplainable shared variable failures that are simply a result of needing to reboot my network switch (unplug for a minute and plug back in). It is usually the hardest problem to track down too.

Let me know if any of this helps.

[HappyDog]

I was using network-published shared variables on a touch panel. The error code was ni_tagger_lvpda_Write. The shared variable would not take data, in fact, it would not initialize. Perhaps, this is the same type of error as what you got. What worked for me is to go to File/Vi Properties/Execution and uncheck the box: Autopreallocate arrays and strings. This unchecked box disappeared if accessed again but the shared variable worked. Hope this helps!