Communicating with Fielpoint devices with network failure

[Joseph_Loo]

I have a Fielpoint system communicationg over the intranet within my company. We use it to monitor the various devices across the network. The application is working fine under Labview 8.0. My understanding since Labview 7.0 they would like us to use the Fieldpoint I/O Point to communicate with the various Fieldpoint modules.

The problem I have, is that sometimes the network goes down, Fieldpoint unit looses power, removal of the device on the network. Using the Fieldpoint I/O Point, it will stop the application when it can not establish communication during the intial startup. I do not care if the device is down, I need to continue running even if some of the Fieldpoint modules is down.

Unfortunately, the older way was to use the Fp Create tag and FP read or write.  Under 8.2, FP Create Tag is not on the standard menu. How do we go about accessing the advance Fieldpoint VI? If we use the I/O Point, will the VI stop the application when we do a read if network communication fail?

[Nadim R]

Hi Joseph Loo,

If I understand your problem correctly, you would like the main application to continue to run, even when a device that you are communicating to loses a connection.  One possible solution is to use the error output code.  A connection lost error code will be outputted once the connection is lost.  From the error output, I would unbundle the error cluster and input the error code to a case structure.   If the error code represents a connection lost, I would clear the error with the clear error vi and continue the application.


Regards,

Nadim R
Applications Engineering
National Instruments

[Joseph_Loo]

I already have the error portion wired up. It stops either on or before the FP read.

[Nadim R]

Hi,

If the error occurs before the FP read, then something other than the read is causing the error.  Would it be possible to attach a printscreen of your block diagram corresponding to the error?  One way to troubleshoot errors is to highlight execution and find out exactly where the error is coming from.  Once we find the cause of the error, we can then use clear error, allowing the application to continue to run.


Regards,

Nadim
Applications Engineering
National Instruments

[Joseph_Loo]

I am wondering if this related to a memory problem associated with windows.. Today I tried running the set of VI and now it is working. Earlier this morning, I changed the Fieldpoint iak file on MAX. The Fieldpoint I/O point would not see the Fieldpoint devices until I rebooted the machine. You could look at MAX, and the all the devices were there. I am wondering if it has to do with a similiar issue, that it could not see the device until you reboot the machine.

If the device comes back on-line will it read the data properly even if it was not available at the start of the program?

[Nadim R]

Hi,

Changing your IAK file in MAX does not neccessarily mean that the new IAK file will be associated in LabVIEW.  You must save your IAK file in MAX.  If the I/O point in LabVIEW does not update with the new channels, click the down arrow on the I/O point and click browse.  Locate where you saved your new IAK file.  The channels should be updated then.  I believe that LabVIEW is not getting the correct IAK file after you have changed it in MAX. 

If you have error handling that clears the error if no connection is found, then you will be able to continue to run the program.  If the IP address on the device does not change and the device comes online, then I would think that the program should work afterwards.


Regards,

Nadim
Applications Engineering
National Instruments

[Joseph_Loo]

Did al those things already. Soon as you rebooted the machine, it started to work.