shared varaible communication

[solarburnDOER]

I am trying to connect to my compact field point using a shared varaible. I have done this successfully on my office computer, moved my compact field point into the test area and am trying to run the same softeware on my lab computer. I get the error something like "could not read shared varaible, likely its not been deployed properly." I am using the first release of labview 8.0.

I have tried the following:

-disableing the windows firewall, then rebooting (winXP)
-deleting the shared varaible, and making a new one.
-avoiding putting spaces in the varaible name

I have full communication, and am using the same MAX setup on both computers.

If others could give me a list of things to try that would be great. Have the subsequent two updates to labview8.0 fixed this?

Short list of things I have not tried:

-using a hub with two ethernet cables, i am using a Xover cable, worked fine in office

Thanks for your help,
Kevan -

[McKala[DE]]

Hello Kevan,

Where are you deploying the shared variable?  Is it on the host computer or is it on the FieldPoint Controller?  You can use the Shared Variable Manager under Tools >> Shared Variable >> Variable Manager to make sure that the variable exists on either the host or the controller.  If the variable doesn't exist in either space you will need to create the variable and then you will be able to bind to it. 

Another option is that the variable is not being deployed.  You can deploy the variable manually by right-clicking on the Library and selecting Deploy all. 

Post again if you are still having problems.

Regards,

[solarburnDOER]

Reply to my post on the Labview forum:

Hi Kevan,

Here are some steps you should try if you have not done so already:

• Run a VI without shared variables from within the same project and verify that front panel communication is working properly
• Verify IP address settings on the lab machine (set to static IP, if so, is it the same as your office machine?)
• How many network interfaces are installed on the system?  If multiple, disable the one not connected to cFP
• What is the actual error number that appears?
• Verify as well that the gateway and dns settings for the lab machine match that of the office machine - this has been known to cause some odd behavior
• Manually deploy the library before running program by right-clicking on the library in the project window and select Deploy All.  Additionally, if the library was not set to Autodeploy, this would also explain the situation.
• Change the hosting location of the library containing the shared variables (i.e., drag from cFP target to your PC in the project window)

One of the above should expose the issue, if not solve it outright.  Please post back once you've had a chance to give it a try.  Have a great weekend!

Cheers,

Matt P.
National Instruments

Well I found one stupid problem but that just leads me to another set of issues. I followed Matt's advice and turned off my other network card. That showed me that I am deploying my shared varaible to the wrong ethernet. I have disabled my extra network adaptor and I see the shared variable deploy to the correct IP address 192.168.1.1.  However this does not solve the problem.

Additionally:
I can not figure out how to have it deploy to the correct address without disabling the other adaptor. How is this done?
I can get the shared varaibles to work if I host them on the fieldpoint, but not on my computer.

Yes I can deploy the varaibles, I can see the time stamp change for the varaible that the VI on My Computer writes to, but I cannot see a change in the varaible that is written to on the fieldpoint.

The actual error number is as follows: 
-1950679035
Error -1950679035 occured at ni_tagger_lv_Read (also Write).

Possible Reasons:
Labview: (Hex 0x8BB0005) Unable to locate varaible in shared variable engine. Deployment of this varaible may have failed

Thanks,
Kevan -

[Chris_Cilino]

Kevan,

Turns out that the shared variable will always deploy to the default nic. So what you could possibly do is change which one of your nics is the default. To do this go to Start>>settings>>double click network connections. From the menu bar select Advanced>>Advanced settings. The top item in the "connections" box is your default.

Can you verify that the variables are actually deployed? You said "I can get the shared varaibles to work if I host them on the fieldpoint",but then "but I cannot see a change in the variable that is written to on the fieldpoint." Is the sv on field point updating... in what sense is it working correctly?

Also, is the -1950679035 error still occuring after you tried disabling the nic?

Try using the variable manager to verify what's deployed and let us know what you find. thanks

Chris C

[solarburnDOER]

Chris,
  Thanks for your help. As soon as i changed the connection to make my fieldpoint my default, my programs worked.
To summerize all the things I learned.

-The shared varaible manager (Tools >> Shared Variable >> Variable Manager) can help to see if your varaibles are deployed and their status.
-When a shared varaible library is deployed, the deploy window shows the IP adderess to which it is deployed.
-The windows firewall blocks shared varaibles - disable it or allow the fieldpoint connection complete access.
-The IP addresses of the target (Fieldpoint) and the Host should be set up correctly in MAX
-Change the hosting location should show if there is a connection problem or a problem with your VI (it works most of the time on the Fieldpoint)
-The shared varaibles deploy to the default ethernet connection:   Start>>settings>>double click network connections. From the menu bar select Advanced>>Advanced settings. The top item in the "connections" box is your default.

Any that I missed might be highlighted in the earlier replies or on one or two other fourms.

Good luck to others with shared varaibles and multiple ethernet connections.