Read LabVIEW shared variables ( network variables?) with VB6

Hi, i need to read some LabVIEW shared variables (network variables?) using a VB6 program.
Is it possible?
I think that yes, using Measurement Studio for VB6 but I don't know how and I haven't found information in the Measurement Studio for VB6 help file
Could some one send me a program example or explain me how it is possible to read LabVIEW shared variables fromVB6?

Hello quintella,
To be able to interface with LabVIEW
Shared Variables with Visual Basic 6 you will need to use NI Measurement
Studio, which ships with examples on how to use VB6 with DataSocketing. Apart
from Data Sockets, if you are using Measurement Studio 8.1 or higer, with the
Network Variable Library introducted in NI Measurement Studio 8.1, you can read
and write to shared variables in ANSI C, Visual Basic .NET or Visual C#. (http://zone.ni.com/devzone/cda/tut/p/id/4679)
Here you have two links where you can
find more information about how to use the datasocket option. In addition, there
are several examples included in Measurement Studio with Network Variables and
Datasocket.
http://forums.ni.com/ni/board/message?board.id=230&message.id=2945&requireLogin=False
http://forums.ni.com/ni/board/message?board.id=230&message.id=3324&requireLogin=False
Regards,

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How do you synchronize accesses to a LabVIEW Shared Variable?

I would like to create an ad-hoc weather station program (I'll explain more in a bit). I am using LabVIEW 8.0 Full Edition, and I would like to share data over a network between stations with the LabVIEW Shared Variable. Here's what I want to be able to do:
A node would start up, and begin publishing data to a network via a shared variable.
The shared variable is an array of clusters
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Wendy,
I am afraid Semaphores are not network-shared objects (to my knowledge), they are system-level objects that use operating-system synchronization mechanisms. If I were synchronizing on a single machine, a semaphore might be a valid mechanism; as an aside, most user-mode semaphores are designed to synchronize within a single process - to synchronize between processes you need to store the semaphore in the Kernel, and to synchronize over a network you would need a network node to handle serialization of requests. My Shared Variable is published over a network, and to my knowledge there are no network-published synchronization mechanisms available - mostly because there is no way to currently perform an atomic test-and-set on the Shared Variable (am I correct?) and there isn't a mechanism for blocking access to a Shared Variable from another network device/machine (or is there?). I've been looking for some way to implement an atomic test-and-set but I am running into a wall; I know that if I select the "single writer" attribute of the Shared Variable I can get LabVIEW to force a single writer allowing me to have an atomic "set", but I need more than that.
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Message Edited by texasdiaz on 02-23-2006 02:52 AM

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Hello
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Hi user42,
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http://forums.ni.com/ni/board/message?board.id=180&message.id=24569&requireLogin=False
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Datasocket with LabWindows/CVI and LabVIEW Real-Time:
http://digital.ni.com/public.nsf/allkb/CC4343488413A2F586256E6200099638?OpenDocument
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NIG

Labview Shared Variable configuration

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Hi Zorro,
I need a little clarification of the particular situation.
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Can any body help me in reading analogue shared variable read in LabVIEW 2009 dynamic event structure. I have tried to read the above tag through Tag Reader VI but i have experienced too much delay in first read for real data i.e. Plant data from PLC. when this particular VI executes it take minutes to display the data. if some needs its code i can provide it. Thanks in advance

First one is On value Change Event Structure
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Attachments:
On value change event.vi ‏24 KB
Read Tag.vi ‏20 KB
On value change event2.vi ‏22 KB

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Can I programmatically change the I/O direction of a LabView shared variable? I'm using LV 2010 and I'm trying to change the I/O direction of a NI 9403 module programmatically. Is this possible?

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Below is a link describing the characteristics of a case structure.
http://zone.ni.com/reference/en-XX/help/371361G-01/glang/case_structure/
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Solved!
Go to Solution.

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I am having a problem reading an array of 20 unsigned integers from an Allen Bradley ControlLogix PLC with Labview.
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Slow performance to read/write shared variables programatically

We are using datasocket read and write functions to read and write shared variables programatically (in the same machine) but we only achieve a performance of aprox. 200 reads/writes per second. We are using Labview 8.6 with DSC.
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Any help would be appreciated. Thank you in advance.

Hi MMCDAT,
I think this value can
be normal as you can see in this link:
http://zone.ni.com/devzone/cda/tut/p/id/5037
As you can see, the
limit for datasocket depends on your Ethernet limitations, even if you as using
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http://digital.ni.com/public.nsf/websearch/6AC9E65734E53F9A8625672400637ECC?OpenDocument
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Hi all I am having a frustrating problem. I am trying to use shared
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Attachments:
PumpMonitoringDevice.zip ‏2083 KB

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Caleb Harris
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Solved!
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Error -1950679035 When Using the LabVIEW Shared Variable

While communication of PLC & labview 2014 SP1 via modbus ethernet I am getting continuously Error -1950679035 as per attachment.
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Attachments:
error.png ‏263 KB

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Keep up to date on the latest PXI news at twitter.com/pxi

Read LabVIEW shared variables ( network variables?) with VB6

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