NI OPC server no DSC

[CJasnoch]

I have been digging around for a while and am having difficulty finding anything that shows me how to get my tags into LabVIEW. I have the OPC drivers for numersou PLCs and are connecting to a GE 9030 (specifically a 341 model). I have set it up in the NI OPC servers and can communicate.

How the heck to I get the tags into LabVIEW. Everything I find using IO Server which is part of DSC which I do not have (and do not plan on getting). I was led to beleive this would not be difficult to read tags in any PLC using these drivers... Any help is greatly appreciated.

[Brinoceros]

Hi CJasnoch,

Communication with OPC servers in LabVIEW without DSC is done via DataSocket.

Check out this Knowledge Base artice, especially the first three links in the "Related Links" section at the bottom.  I think this is what you are looking for!

[LabBEAN]

The link that Brian provided:

http://digital.ni.com/public.nsf/allkb/DD1E23328AF0A303862570A4006F4134

states the following:

"If your application uses a subset of the DSC Module that does not require the RTS, it is still necessary to include the Enhanced DSC Deployment Support in your installer.  For more information about which DSC functionality requires the RTS and which does not, refer to the related links."

One of those links was this one:

http://zone.ni.com/devzone/cda/tut/p/id/3061

Which states:

"The LabVIEW DSC Run-Time System correctly installs the necessary and additional software as well as provides all the configuration tools, the Tag Engine, historical data logging, network data access, security, and other features provided by the LabVIEW DSC Module."

There seem to be 4 components here:

DSC Development System (~$2600)

DSC Run-Time System (~$800)

Enhanced DSC Deployment Support for LabVIEW 8.x (free add on installer when you have DSC Development System)

Enhanced DSC Run-Time Support  (Can be checked inside LabVIEW project when you're building an application)

Which features can be used in a deployed application (EXE) without purchasing the $800 DSC RTS (Run-Time System)?

When do I check the "Enable Enhanced DSC Run-Time Support" box when I build the EXE?

When do I include "Enhanced DSC Deployment Support for LabVIEW 8.x" when I build my installer?

OPC is not listed above with "configuration tools, the Tag Engine, historical data logging, network data access, security".

Can I bind a Shared Variable to an OPC tag without DSC Development System or DSC RTS?

I seem to be able to deploy a library with my OPC I/O server (which I created with my DSC Development System) and a library with my shared variables to the target PC.  However, when browsing with DSM (Distributed System Manager -- which I downloaded and installed on the PC), while I can see both server and variable processes, the I/O server is not listed under the server process.  The dependent shared variables are listed in the variable process.  There are no variables included in the server LVLIB.  All dependencies reside in the variable library -- which seems to be deploying fine, despite some admonitions indicating the contrary.  The library with the server may not be deploying because I need the DSC RTS to deploy an OPC I/O server.  This same behavior has been duplicated on a PC with LabVIEW without DSC installed.

Clear as mud?  Thanks for the help!

Message Edited by LabBEAN on 02-13-2009 05:31 PM

[LabBEAN]

Error code during deployment of the server library is "1" (using the Deploy Libraries Invoke Node).  This error will occur if the Variable Engine is not installed.  Mine is, and the service is running -- more on that below.

I get error -1950679037 (Server Failure), which I get when I try to read a shared variable (presumably because there is no I/O server deployed).

The KB here:

http://digital.ni.com/public.nsf/allkb/9D1690C5B1CE1D25862572FA0053150D

suggests that you do one of the following to clear error -1950679037:

1) "Change the Identity Property of the OPC Server" to "the interactive user"

 -- this DCOM setting is not available when NI OPC Servers is configured to run as a service.  Running as a service (Tools >> Options >> Service tab), is the only way that NI recommends you run NI OPC Servers (or there are many other problems).  So, "the interactive user" is not a viable option.

2) "Change the Log On Account for the SVE Service" to Administrator.

--when I do this and restart the NIVE service, I get Windows error 1069.  I've checked and "Administrator" is listed under Local Security Policy >> User Rights Assignment >> Log on as a service, which is the recommended solution for this error code.  So, the NIVE  Logon is still "Local System account".

See attached screen shot.

Thanks again...

Message Edited by LabBEAN on 02-13-2009 06:24 PM

[Robbob]

Jason and I have had a chance to work on this together, and our findings have shown that most of these errors stem from the fact that the DSC Run-Time System is required whenever an I/O server needs to be deployed on a target computer.  The workaround for this is, as Brinocerous mentioned, to use Datasockets.

As for the error 1 message, this seems to stem from 3 possible situations:

1) A general path error.

2) Shared Variable Engine is not started, be sure this is installed and running on your target computer.  Distributed system manager is a great tool for checking this, and can be installed independently through either an installer or off of our website.

3) The DSC RTS is required and is not installed.  I agree that this is a vague error and could use more description, as it is hard to decode that the RTS is required with an error 1 message, which is usually reserved for incorrect paths.

 It is recommended to run the NI OPC servers as a service.  This is not the default option as it should be it seems.  This can be enabled by opening NI OPC server, opening tools->options->service and checking the 'Run as a Windows NT Service' check box.  When this is run as a service, NI OPC service cannot be run as interactive user.  This option will be grayed out, however other OPC servers may allow this functionality, and that is why the KB exists. This will have to be researched before any changes are made to that KnowledgeBase, however it will be updated to reflect that fact that NI OPC servers will not allow this.

The error reported when running as an administrator was reproduced on my end as well with NI OPC servers, but it is possible it may resolve some issues with other OPC servers.  The KnowledgeBase will be updated to reflect that fact.

I will try and respond when more information is available.  If anyone else is having errors similar to this, please either post here or go to ni.com/ask and open up a service request so that we can help you out.  We would like to get this all straightened out so that it is as straightforward as possible, and Jason's discoveries have made it clear that more documentation needs to be provided on these types of setups.