What is the best approach to converting LV7.1 tags to LV2012 shared variables in multiple VIs?

[lebecker]

What is the best approach to upgrading from LV7.1/DSC tags to LV2012/DSC shared variables, in multiple VIs running on multiple platforms? Our system is composed of  about 5 PCs running Windows 2000/LV7.1 Runtime, plus a PLC, and a main controller running XP/SP3/LV2012. About 3 of the PCs publish sensor information via tags across the LAN to the main controller. Only the main controller is currently being upgraded. Rudimentary questions:

1. Will the other PCs running the 7.1 RTE (with tags) be able to communicate with the main controller running 2012 (shared variables)?

2. Is it necessary to convert from tags to shared variables, or will the deprecated legacy tag VIs from LV7.1 work in LV2012?

3. Will all the main controller VIs need to be incorporated into a project in order to use shared variables?

4. Is the only way to do this is to find all tag items and replace them with shared variable items?

Thanks in advance with any information and advice!

lb

[Dave.C]

Hi lb,

We're glad to hear you're upgrading, but because there was a fundamental change in architecture since version 7.1, there will likely be some portions that require a rewrite. 

The RTE needs to match the version of DSC your using.  Also, the tag architecture used in 7.1 is not compatible with the shared variable approach used in 2012.  Please see the KnowledgeBase article Do I Need to Upgrade My DSC Runtime Version After Upgrading the LabVIEW DSC Module?

You will also need to convert from tags to shared variables.  The change from tags to shared variables took place in the transition to LabVIEW 8.  The KnowledgeBase Migrating from LabVIEW DSC 7.1 to 8.0 gives the process for changing from tags to shared variables. 

Hope this gets you headed in the right direction.  Let us know if you have more questions.

Thanks,

[lebecker]

Thanks Dave,

I feared this was the answer after perusing the documents...just one other question: Since the other PCs running LV/DSC 7.1 will not be upgraded, I take it that the 7.1 RTE using tags on these boxes will be incompatible with the shared variable environment the publisher (running LV/DSC 2012) will be using? Is the workaround here to revert to datasockets so these different versions will have a common medium over which to communicate their data? 

Thanks for your response, Dave

lb

[Dave.C · Accepted solution]

Hi lb,

Datasockets are the only common medium I'm aware of between the two versions, so aside from upgrading everything to the same version, they'll likely be your best bet.