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Sharing a shared network variable between two PC's connected to a network

Sharing a shared network variable between two PC's connected to a network Surely this shouldn’t be so difficult! I have a little LabVIEW program running in the background of PC1. The exe’s task is to collect and send OPC variables held on a SCADA system and convert them to shared network variables (as I thought that they would be easy to share over a network, easier than the nasty OPC and DCOM issues). I have PC2 which runs measurement studio and I have created a nice test VB program which either writes or reads the network variables which are on PC1. The PC1 collection software is working perfectly and when I change the values on the SCADA system I can see the network variable change on ‘NI Distributed System Manager’. I When I look at ‘NI Distributed System Manager’ on PC2 I can’t see PC1 on the list and when I use the basic measurement studio code below to read the network variable it times out at the TestVariable.connect() line. Ok so what do I need to do to read a shared network variable sat on PC1 from PC2 on the network Public Class Form1 Private WithEvents TestVariable As NetworkVariableSubscriber(Of Double) Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load TestVariable = New NetworkVariableSubscriber(Of Double)("\\192.168.58.139\Test\TestVariable") TestVariable.Connect() End Sub Private Sub TestVariable_Data_Updated(ByVal sender As System.Object, ByVal e As NationalInstruments.NetworkVariable.DataUpdatedEventArgs(Of Double)) Handles TestVariable.DataUpdated TextBox1.Text = e.Data.GetValue End Sub End Class
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Message 1 of 5
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Sorry lost all the formatting

 

Surely this shouldn’t be so difficult! I have a little LabVIEW program running in the background of PC1. The exe’s task is to collect and send OPC variables held on a SCADA system and convert them to shared network variables (as I thought that they would be easy to share over a network, easier than the nasty OPC and DCOM issues). I have PC2 which runs measurement studio and I have created a nice test VB program which either writes or reads the network variables which are on PC1. The PC1 collection software is working perfectly and when I change the values on the SCADA system I can see the network variable change on ‘NI Distributed System Manager’. I When I look at ‘NI Distributed System Manager’ on PC2 I can’t see PC1 on the list and when I use the basic measurement studio code below to read the network variable it times out at the TestVariable.connect() line.

 

Ok so what do I need to do to read a shared network variable sat on PC1 from PC2 on the network

 

Public Class Form1

    Private WithEvents TestVariable As NetworkVariableSubscriber(Of Double)

 

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        TestVariable = New NetworkVariableSubscriber(Of Double)("\\192.168.58.139\Test\TestVariable")

        TestVariable.Connect()

End Sub

 

Private Sub TestVariable_Data_Updated(ByVal sender As System.Object, ByVal e As NationalInstruments.NetworkVariable.DataUpdatedEventArgs(Of Double)) Handles TestVariable.DataUpdated

TextBox1.Text = e.Data.GetValue

End Sub

End Class 

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Message 2 of 5
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You should probably post this on the Measurement Studio forum since it sounds like the problem is in the Meas. Studio/Shared Variable communication rather than LabVIEW/Shared Variable.

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Message 3 of 5
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Could do although its not about Measurement Studio either, if I built an LabVIEW exe to look for a shared variable which was on another PC I am pretty sure I wouldn't see it either. The problem I am having is the ability to pass a shared variable between two PC's. When talking about shared variable's, NI always talk's about putting it on a RT device I wonder if it not only to do with performance but with the ability to connect a PC to those shared variables is easier between a PC and RT device than it is between two PC's?

 

 

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Message 4 of 5
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Actually just found this

Using the LabVIEW Shared Variable

 

and even more relevant

How Do I Set Up Shared Variables to Communicate Between Two PCs?


Neither PC has development version of LabVIEW. Does anyone know what the PSP URL format is if I had a library in a project called Test and in that it had a Shared Variable called TestVariable would the PSP URL be \\192.168.1.1\Test\TestVariable??

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Message 5 of 5
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