How do I best upgrade a multiworkstation app using DSC from LV7.2 to 8.6?

[RavensFan]

Upgrade to the latest/greatest.  Unless there is some bug listed for 8.6 that would directly affect what you are doing.  If Nickerbocker has a particular concern regarding 8.6, then he should share the details.

[hecmar.arreola]

I hate to just spread FUD, but the issues I've had with 8.6 are very hard for me to nail down specifically.  In general, code that ran great in 8.2 does not run as well in 8.6.  I get "Out of Memory" errors (when Windows clearly has enough disk space and free RAM), and various random lock-ups.  This is from clean installs of 8.6 and I have noticed the problems on more than one machine.

I've also had issues with compiling programs locking labview up, as well as building installers locking things up.  The number of times I have had to visit the windows task manager to end the LabVIEW process has increased from 8.2 to 8.6 and it has left me with a very bad taste in my mouth about 8.6.

Now, the DSC module (which I have no experience with)  might run infinitly better in 8.6 than it did in 7.2.

Having the latest doesn't alway equate to having the greatest, Ravens.  In almost all industriest that utilize LabVIEW stability should be paramound to new features.  If the OP desires features in v8.6 that aren't available in 7.1, then by all means upgrade.  But I am against an upgrade just for upgrade sake.

[RavensFan]

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Nickerbocker wrote:

Having the latest doesn't alway equate to having the greatest, Ravens.  In almost all industriest that utilize LabVIEW stability should be paramound to new features.  If the OP desires features in v8.6 that aren't available in 7.1, then by all means upgrade.  But I am against an upgrade just for upgrade sake.

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I won't disagree with you there.  Certainly you want to use the version that is most stable for your application.  So far, I've found 8.6 to be more reliable than any of the previous versions.  I remember one of the earlier versions 8.2, but perhaps it was 8.0, would crash frequently.  I've had minimal problems with 8.6.  It seems that the slow initial update of bound shared variables that was present in earlier versions has improved.  (See here and here)  Perhaps you are using features in 8.6 that I don't use that have caused you problems.

Just because something is the latest, certainly doesn't make it the greatest, although we sure hope it would.  In general you would hope that more recent versions would solve the bugs from the earlier versions, and hopefully nothing regresses in the process where old bugs get reintroduced (and it seems that doesn happen).  Of course any new features that are introduced which are great to have, could be eligible to have new bugs because they are new.

I think the original poster should try to make the jump to the latest unless there is some specific feature of 8.6 that is flawed and would be a show stopper.  Perhaps browsing the know issues list as pointed to in this thread will help.  The change in the DSC module from 7.1 to 8.x was dramatic.  I think the original poster is making the right move by asking about it and learning all the catches before diving right into this change.

[unclebump]

If it ain't broke, why upgrade at all?? What features are you going to gain in version 8.6 that you do not have in version 7.2. I haven't messed with the shared variable system yet, but it seems like it is still a work in progress. Some of the forum comments make it seem like it has left out things that could be done with the tag engine. Can you afford to not be able to run your system for awhile during the debug phase??

[Charlie_P]

Good Evening Kevin R,

I would definitely suggest the upgrade to LabVIEW 8.6 (and maybe DSC 8.6).  Besides having the latest and greatest (whose merits have been discussed in previous posts), you will ensure an easier time of upgrading another few years from now when you might decide that you do want the latest and greatest.  Generally folks who do not like upgrading are those who have the hardest time doing so because they wait for so long.  I commend you for wanting to upgrade now, before it will be too difficult.  You said you have SSP and, as such, all of the appropriate upgrades, so this is a truly unbiased suggestion.

One document that you will want to look through is the Release and Upgrade Notes, LVDSC 8.0. While you will hopefully be upgrading directly to LabVIEW 8.6 instead of 8.0, there are fewer major differences between 8.0 and 8.6.1 than 7.x to 8.0, so this document will outline the major revisions that Ben has already mentioned.  (Note:  One update to the above document that I noticed while skimming through is on page 11.  The Published Variable Monitor has added functionality and is now the Distributed System Manager 8.6.)

As far as the line up from the older to the newer names, the quick list, off the top of my head, is Tag Manager evolved to the Shared/Published Variable Monitor, evolved to the Variable Manager, evolved to the Distributed System Manager.  Each name change essentially retains the core functionality of the previous program buts adds functionality.

Also, as Ben mentioned, you may not need LabVIEW DSC for this project.  DSC includes the added functionality of advanced logging to a Citadel database and alarming.  If you do not log and alarm, DSC may not be needed.  Additionally, any LabVIEW Development System (Base, Full, Professional) can use the DataSocket VIs, which can read/write tags from/to an existing OPC Server.  If you go with this method, you will get into the efficiency concerns that have been voiced in earlier posts.

When used properly, datasockets will perform very similarly during run-time to the Shared Network Variables created under an OPC Client I/O Server within DSC.  Again, this is when they are used properly, which consists of opening and closing references as appropriate when programming.  (i.e. You do not want to repeat the open, do, close sequence within a loop.  Rather, the appropriate method is to open, do in a loop, close the reference.)

You may also want to take a look at the LabVIEW Help entry entitled "Using the Shared Variable Engine (DSC Module)" (LabVIEW Help » DSC Module » Managing I/O with Shared Variables » Concepts » Using the Shared Variable Engine)) for information on using dynamic vs. static addressing of your variables.

The following KnowledgeBase article may be of some assistance later:  Migrating from LabVIEW DSC 7.1 to 8.0

http://digital.ni.com/public.nsf/allkb/B4FF7B27441C0AE1862570F9005F2E94